# Quiz 7: Random Variables and Discrete Probability Distributions

Statistics

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Q 3Q 3

The Poisson random variable is a discrete random variable with infinitely many possible values.

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Q 4Q 4

The mean of a Poisson distribution, where is the average number of successes occurring in a specified interval, is .

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Q 5Q 5

The number of accidents that occur at a busy intersection in one month is an example of a Poisson random variable.

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Q 6Q 6

The number of customers arriving at a department store in a 5-minute period has a Poisson distribution.

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Q 7Q 7

The number of customers making a purchase out of 30 randomly selected customers has a Poisson distribution.

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Q 9Q 9

The Poisson distribution is applied to events for which the probability of occurrence over a given span of time, space, or distance is very small.

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Q 12Q 12

Which of the following cannot have a Poisson distribution?
A) The length of a movie.
B) The number of telephone calls received by a switchboard in a specified time period.
C) The number of customers arriving at a gas station in Christmas day.
D) The number of bacteria found in a cubic yard of soil.

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Multiple Choice

Q 13Q 13

The Sutton police department must write, on average, 6 tickets a day to keep department revenues at budgeted levels.Suppose the number of tickets written per day follows a Poisson distribution with a mean of 6.5 tickets per day.Interpret the value of the mean.
A) The mean has no interpretation.
B) The expected number of tickets written would be 6.5 per day.
C) Half of the days have less than 6.5 tickets written and half of the days have more than 6.5 tickets written.
D) The number of tickets that is written most often is 6.5 tickets per day.

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Multiple Choice

Q 14Q 14

The Poisson random variable is a:
A) discrete random variable with infinitely many possible values.
B) discrete random variable with finite number of possible values.
C) continuous random variable with infinitely many possible values.
D) continuous random variable with finite number of possible values.

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Multiple Choice

Q 15Q 15

Given a Poisson random variable X, where the average number of successes occurring in a specified interval is 1.8, then P(X = 0) is:
A) 1.8
B) 1.3416
C) 0.1653
D) 6.05

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Q 16Q 16

In a Poisson distribution, the:
A) mean equals the standard deviation.
B) median equals the standard deviation.
C) mean equals the variance.
D) None of these choices.

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Q 17Q 17

On the average, 1.6 customers per minute arrive at any one of the checkout counters of Sunshine food market.What type of probability distribution can be used to find out the probability that there will be no customers arriving at a checkout counter in 10 minutes?
A) Poisson distribution
B) Normal distribution
C) Binomial distribution
D) None of these choices.

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Q 18Q 18

A community college has 150 word processors.The probability that any one of them will require repair on a given day is 0.025.To find the probability that exactly 25 of the word processors will require repair, one will use what type of probability distribution?
A) Normal distribution
B) Poisson distribution
C) Binomial distribution
D) None of these choices.

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Q 19Q 19

In a Poisson experiment, the number of successes that occur in any interval of time is ____________________ of the number of success that occur in any other interval.

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Q 20Q 20

In a(n) ____________________ experiment, the probability of a success in an interval is the same for all equal-sized intervals.

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Q 21Q 21

In a Poisson experiment, the probability of a success in an interval is ____________________ to the size of the interval.

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Q 22Q 22

In Poisson experiment, the probability of more than one success in an interval approaches ____________________ as the interval becomes smaller.

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Q 23Q 23

A Poisson random variable is the number of successes that occur in a period of ____________________ or an interval of ____________________ in a Poisson experiment.

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Q 24Q 24

The ____________________ of a Poisson distribution is the rate at which successes occur for a given period of time or interval of space.

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Q 29Q 29

Compute the following Poisson probabilities (to 4 decimal places) using the Poisson formula:
a.
P(X = 3), if = 2.5
b.
P(X 1), if = 2.0
c.
P(X 2), if = 3.0

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Q 30Q 30

Let X be a Poisson random variable with = 6.Use the table of Poisson probabilities to calculate:
a.
P(X 8)
b.
P(X = 8)
c.
P(X 5)
d.
P(6 X 10)

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Q 31Q 31

Let X be a Poisson random variable with = 8.Use the table of Poisson probabilities to calculate:
a.
P(X 6)
b.
P(X = 4)
c.
P(X 3)
d.
P(9 X 14)

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Q 32Q 32

911 Phone Calls
911 phone calls arrive at the rate of 30 per hour at the local call center.
-{911 Phone Calls Narrative} Find the probability of receiving two calls in a five-minute interval of time.

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Q 33Q 33

911 Phone Calls
911 phone calls arrive at the rate of 30 per hour at the local call center.
-{911 Phone Calls Narrative} Find the probability of receiving exactly eight calls in 15 minutes.

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Q 34Q 34

911 Phone Calls
911 phone calls arrive at the rate of 30 per hour at the local call center.
-{911 Phone Calls Narrative} If no calls are currently being processed, what is the probability that the desk employee can take four minutes break without being interrupted?

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Q 35Q 35

Classified Department Phone Calls
A classified department receives an average of 10 telephone calls each afternoon between 2 and 4 P.M.The calls occur randomly and independently of one another.
-{Classified Department Phone Calls Narrative} Find the probability that the department will receive 13 calls between 2 and 4 P.M.on a particular afternoon.

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Q 36Q 36

Classified Department Phone Calls
A classified department receives an average of 10 telephone calls each afternoon between 2 and 4 P.M.The calls occur randomly and independently of one another.
-{Classified Department Phone Calls Narrative} Find the probability that the department will receive seven calls between 2 and 3 P.M.on a particular afternoon.

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Q 37Q 37

Classified Department Phone Calls
A classified department receives an average of 10 telephone calls each afternoon between 2 and 4 P.M.The calls occur randomly and independently of one another.
-{Classified Department Phone Calls Narrative} Find the probability that the department will receive at least five calls between 2 and 4 P.M.on a particular afternoon.

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Q 38Q 38

Post office
The number of arrivals at a local post office between 3:00 and 5:00 P.M.has a Poisson distribution with a mean of 12.
-{Post Office Narrative} Find the probability that the number of arrivals between 3:00 and 5:00 P.M.is at least 10.

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Q 39Q 39

Post office
The number of arrivals at a local post office between 3:00 and 5:00 P.M.has a Poisson distribution with a mean of 12.
-{Post Office Narrative} Find the probability that the number of arrivals between 3:30 and 4:00 P.M.is at least 10.

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Q 40Q 40

Post office
The number of arrivals at a local post office between 3:00 and 5:00 P.M.has a Poisson distribution with a mean of 12.
-{{Post Office Narrative} Find the probability that the number of arrivals between 4:00 and 5:00 P.M.is exactly two.

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Q 41Q 41

Suppose that the number of buses arriving at a Depot per minute is a Poisson process.If the average number of buses arriving per minute is 3, what is the probability that exactly 6 buses arrive in the next minute?

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Q 42Q 42

Unsafe Levels of Radioactivity
The number of incidents at a nuclear power plant has a Poisson distribution with a mean of 6 incidents per year.
-{Unsafe Levels of Radioactivity Narrative} Find the probability that there will be exactly 3 incidents in a year.

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Q 43Q 43

Unsafe Levels of Radioactivity
The number of incidents at a nuclear power plant has a Poisson distribution with a mean of 6 incidents per year.
-{Unsafe Levels of Radioactivity Narrative} Find the probability that there will be at least 3 incidents in a year.

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Q 44Q 44

Unsafe Levels of Radioactivity
The number of incidents at a nuclear power plant has a Poisson distribution with a mean of 6 incidents per year.
-{Unsafe Levels of Radioactiviy Narrative} Find the probability that there will be at least 1 incident in a year.

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Q 45Q 45

Unsafe Levels of Radioactivity
The number of incidents at a nuclear power plant has a Poisson distribution with a mean of 6 incidents per year.
-{Unsafe Levels of Radioactivity Narrative} Find the probability that there will be no more than 1 incident in a year.

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Q 46Q 46

Unsafe Levels of Radioactivity
The number of incidents at a nuclear power plant has a Poisson distribution with a mean of 6 incidents per year.
-{Unsafe Levels of Radioactivity Narrative} Find the variance of the number of incidents in one year.

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Q 47Q 47

Unsafe Levels of Radioactivity
The number of incidents at a nuclear power plant has a Poisson distribution with a mean of 6 incidents per year.
-{Unsafe Levels of Radioactivity Narrative} Find the standard deviation of the number of incidents is in one year.

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Q 49Q 49

A random variable is a function or rule that assigns a number to each outcome of an experiment.

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Q 51Q 51

The mean of a discrete probability distribution for X is the sum of all possible values of X, divided by the number of possible values of X.

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Q 52Q 52

The length of time for which an apartment in a large complex remains vacant is a discrete random variable.

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Q 54Q 54

A continuous variable may take on any value within its relevant range even though the measurement device may not be precise enough to record it.

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Q 55Q 55

Given that X is a discrete random variable, then the laws of expected value and variance can be applied to show that E(X + 5) = E(X) + 5, and V(X + 5) = V(X) + 25.

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Q 56Q 56

A table, formula, or graph that shows all possible values a random variable can assume, together with their associated probabilities, is referred to as probability distribution.

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Q 57Q 57

Faculty rank (professor, associate professor, assistant professor, and lecturer) is an example of a discrete random variable.

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Q 58Q 58

For a random variable X, if V(cX) = 4V(X), where V refers to the variance, then c must be 2.

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Q 63Q 63

A table, formula, or graph that shows all possible values a random variable can assume, together with their associated probabilities, is called a(n):
A) probability distribution.
B) discrete random variable.
C) expected value of a discrete random variable.
D) None of these choices.

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Multiple Choice

Q 64Q 64

A function or rule that assigns a numerical value to each outcome of an experiment is called:
A) a sample space.
B) a probability distribution.
C) a random variable.
D) None of these choices.

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Q 65Q 65

The weighted average of the possible values that a random variable X can assume, where the weights are the probabilities of occurrence of those values, is referred to as the:
A) variance.
B) standard deviation.
C) expected value.
D) None of these choices.

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Multiple Choice

Q 66Q 66

The number of accidents that occur annually on a busy stretch of highway is an example of:
A) a discrete random variable.
B) a continuous random variable.
C) expected value of a discrete random variable.
D) expected value of a continuous random variable.

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Multiple Choice

Q 67Q 67

Which of the following are required conditions for the distribution of a discrete random variable X that can assume values x

_{i}? A) 0 p(x_{i}) 1 for all x_{i}B) C) Both a and b are required conditions. D) Neither a nor b are required conditions.Free

Multiple Choice

Q 68Q 68

Which of the following is not a required condition for the distribution of a discrete random variable X that can assume values x

_{i}? A) 0 p(x_{i}) 1 for all x_{i}B) C) p(x_{i}) > 1 for all x_{i}D) All of these choices are true.Free

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Q 69Q 69

A lab at the DeBakey Institute orders 150 rats a week for each of the 52 weeks in the year for experiments that the lab conducts.Suppose the mean cost of rats used in lab experiments turned out to be $20.00 per week.Interpret this value.
A) Most of the weeks resulted in rat costs of $20.00
B) The median cost for the distribution of rat costs is $20.00
C) The expected or average costs for all weekly rat purchases is $20.00
D) The rat cost that occurs more often than any other is $20.00

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Q 70Q 70

In the notation below, X is the random variable, c is a constant, and V refers to the variance.Which of the following laws of variance is not true?
A) V(c) = 0
B) V(X + c) = V(X) + c
C) V(cX) = c

^{2}V(X) D) None of these choices.Free

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Q 71Q 71

Which of the following is a discrete random variable?
A) The Dow Jones Industrial average.
B) The volume of water in Michigan Lakes.
C) The time it takes you to drive to school.
D) The number of employees of a soft drink company.

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Q 72Q 72

Which of the following is a continuous random variable?
A) The number of employees of an automobile company.
B) The amount of milk produced by a cow in one 24-hour period.
C) The number of gallons of milk sold at Albertson's grocery store last week.
D) None of these choices.

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Q 73Q 73

In the notation below, X is the random variable, E and V refer to the expected value and variance, respectively.Which of the following is false?
A) E(3X) = 3E(X)
B) V(2) = 0
C) E(X + 1) = E(X) + 1
D) All of these choices are true.

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Q 74Q 74

A motorcycle insurance company evaluates many numerical variables about a person before deciding on an appropriate rate for motorcycle insurance.How long a person has been a licensed rider is an example of a(n) ____________________ random variable.

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Q 75Q 75

An auto insurance company evaluates many numerical variables about a person before deciding on an appropriate rate for automobile insurance.The number of claims a person has made in the last 3 years is an example of a(n) ____________________ random variable.

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Q 76Q 76

An auto insurance company evaluates many numerical variables about a person before deciding on an appropriate rate for automobile insurance.A person's age is an example of a(n) ____________________ random variable.

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Q 77Q 77

A motorcycle insurance company evaluates many numerical variables about a person before deciding on an appropriate rate for motorcycle insurance.The number of tickets a person has received in the last 3 years is an example of a(n) ____________________ random variable.

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Q 78Q 78

A motorcycle insurance company evaluates many numerical variables about a person before deciding on an appropriate rate for motorcycle insurance.The distance a person rides in a year is an example of a(n) ____________________ random variable.

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Q 79Q 79

The dean of students conducted a survey on campus.Grade point average (GPA) is an example of a(n) ____________________ random variable.

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Q 80Q 80

The amount of time that a microcomputer is used per week is an example of a(n) ____________________ random variable.

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Q 81Q 81

The number of days that a microcomputer goes without a breakdown is an example of a(n) ____________________ random variable.

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Q 84Q 84

For each of the following random variables, indicate whether the variable is discrete or continuous, and specify the possible values that it can assume.
a.
X = the number of traffic accidents in Albuquerque on a given day.
b.
X = the amount of weight lost in a month by a randomly selected dieter.
c.
X = the average number of children per family in a random sample of 175 families.
d.
X = the number of households out of 10 surveyed that own a convection oven.
e.
X = the time in minutes required to obtain service in a restaurant.

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Q 85Q 85

Number of Motorcycles
The probability distribution of a discrete random variable X is shown below, where X represents the number of motorcycles owned by a family.
-{Number of Motorcycles Narrative} Find the following probabilities:
a.
P(X > 1)
b.
P(X 2)
c.
P(1 X 2)
d.
P(0 < X < 1)
e.
P(1 X < 3)

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Q 86Q 86

Number of Motorcycles
The probability distribution of a discrete random variable X is shown below, where X represents the number of motorcycles owned by a family.
-{Number of Motorcycles Narrative} Find the expected value of X.

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Q 87Q 87

Number of Motorcycles
The probability distribution of a discrete random variable X is shown below, where X represents the number of motorcycles owned by a family.
-{Number of Motorcycles Narrative} Find the standard deviation of X.

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Q 88Q 88

Number of Motorcycles
The probability distribution of a discrete random variable X is shown below, where X represents the number of motorcycles owned by a family.
-{Number of Motorcycles Narrative} Apply the laws of expected value to find the following:
a.
E(X

^{2}) b. E(2X^{2}+ 5) c. E(X 2)^{2}Free

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Q 89Q 89

Number of Motorcycles
The probability distribution of a discrete random variable X is shown below, where X represents the number of motorcycles owned by a family.
-{Number of Motorcycles Narrative} Apply the laws of expected value and variance to find the following:
a.
V(3X)
b.
V(3X 2)
c.
V(3)
d.
V(3X) 2

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Q 90Q 90

Number of Horses
The random variable X represents the number of horses per family in a rural area in Iowa, with the probability distribution: p(x) = 0.05x, x = 2, 3, 4, 5, or 6.
-{Number of Horses Narrative} Express the probability distribution in tabular form.

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Q 91Q 91

Number of Horses
The random variable X represents the number of horses per family in a rural area in Iowa, with the probability distribution: p(x) = 0.05x, x = 2, 3, 4, 5, or 6.
-{Number of Horses Narrative} Find the expected number of horses per family.

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Q 92Q 92

Number of Horses
The random variable X represents the number of horses per family in a rural area in Iowa, with the probability distribution: p(x) = 0.05x, x = 2, 3, 4, 5, or 6.
-{Number of Horses Narrative} Find the variance and standard deviation of X.

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Q 93Q 93

Blackjack
The probability distribution of a random variable X is shown below, where X represents the amount of money (in $1,000s) gained or lost in a particular game of Blackjack.
-{Blackjack Narrative} Find the following probabilities:
a.
P(X 0)
b.
P(X > 3)
c.
P(0 X 4)
d.
P(X = 5)

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Q 94Q 94

Blackjack
The probability distribution of a random variable X is shown below, where X represents the amount of money (in $1,000s) gained or lost in a particular game of Blackjack.
-{Blackjack Narrative} Find the following values and indicate their units.
a.
E(X)
b.
V(X)
c.
Standard deviation of X

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Q 95Q 95

Gym Visits
Let X represent the number of times a student visits a gym in a one month period.Assume that the probability distribution of X is as follows:
-{Gym Visits Narrative} Find the mean and the standard deviation of this distribution.

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Q 96Q 96

Gym Visits
Let X represent the number of times a student visits a gym in a one month period.Assume that the probability distribution of X is as follows:
-{Gym Visits Narrative} Find the mean and the standard deviation of Y = 2X 1.

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Q 97Q 97

Gym Visits
Let X represent the number of times a student visits a gym in a one month period.Assume that the probability distribution of X is as follows:
-{Gym Visits Narrative} What is the probability that the student visits the gym at least once in a month?

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Q 98Q 98

Gym Visits
Let X represent the number of times a student visits a gym in a one month period.Assume that the probability distribution of X is as follows:
-{Gym Visits Narrative} What is the probability that the student visits the gym at most twice in a month?

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Q 99Q 99

The monthly sales at a Gas Station have a mean of $50,000 and a standard deviation of $6,000.Profits are calculated by multiplying sales by 40% and subtracting fixed costs of $12,000.Find the mean and standard deviation of monthly profits.

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Q 100Q 100

Shopping Outlet
A shopping outlet estimates the probability distribution of the number of stores shoppers actually enter as shown in the table below.
-{Shopping Outlet Narrative} Find the expected value of the number of stores entered.

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Q 101Q 101

Shopping Outlet
A shopping outlet estimates the probability distribution of the number of stores shoppers actually enter as shown in the table below.
-{Shopping Outlet Narrative} Find the variance and standard deviation of the number of stores entered.

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Q 102Q 102

Shopping Outlet
A shopping outlet estimates the probability distribution of the number of stores shoppers actually enter as shown in the table below.
-{Shopping Outlet Narrative} Suppose Y = 2X + 1 for each value of X.What is the probability distribution of Y?

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Q 103Q 103

Shopping Outlet
A shopping outlet estimates the probability distribution of the number of stores shoppers actually enter as shown in the table below.
-{Shopping Outlet Narrative} Calculate the expected value of Y directly from the probability distribution of Y.

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Q 104Q 104

Shopping Outlet
A shopping outlet estimates the probability distribution of the number of stores shoppers actually enter as shown in the table below.
-{Shopping Outlet Narrative} Use the laws of expected value to calculate the mean of Y from the probability distribution of X.

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Q 105Q 105

Shopping Outlet
A shopping outlet estimates the probability distribution of the number of stores shoppers actually enter as shown in the table below.
-{Shopping Outlet Narrative} Calculate the variance and standard deviation of Y directly from the probability distribution of Y.

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Q 106Q 106

Shopping Outlet
A shopping outlet estimates the probability distribution of the number of stores shoppers actually enter as shown in the table below.
-{Shopping Outlet Narrative} Use the laws of variance to calculate the variance and standard deviation of Y from the probability distribution of X.

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Q 107Q 107

Shopping Outlet
A shopping outlet estimates the probability distribution of the number of stores shoppers actually enter as shown in the table below.
-{Shopping Outlet Narrative} What did you notice about the mean, variance, and standard deviation of Y = 2X + 1 in terms of the mean, variance, and standard deviation of X?

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Q 108Q 108

Retries
The following table contains the probability distribution for X = the number of retries necessary to successfully transmit a 1024K data package through a double satellite media.
-{Retries Narrative} What is the probability of no retries?

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Q 109Q 109

Retries
The following table contains the probability distribution for X = the number of retries necessary to successfully transmit a 1024K data package through a double satellite media.
-{Retries Narrative} What is the probability of a least one retry?

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Q 110Q 110

Retries
The following table contains the probability distribution for X = the number of retries necessary to successfully transmit a 1024K data package through a double satellite media.
-{Retries Narrative} What is the mean or expected value for the number of retries?

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Q 111Q 111

Retries
The following table contains the probability distribution for X = the number of retries necessary to successfully transmit a 1024K data package through a double satellite media.
-{Retries Narrative} What is the variance for the number of retries?

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Q 112Q 112

Retries
The following table contains the probability distribution for X = the number of retries necessary to successfully transmit a 1024K data package through a double satellite media.
-{Retries Narrative} What is the standard deviation of the number of retries?

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Q 115Q 115

If X and Y are independent variables with V(X) = 23.48 and V(Y) = 36.52, then the standard deviation of W = X + Y is

_{w}= 7.746.Free

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Q 120Q 120

If X and Y are two variables with , , and COV(X, Y) = 11.76, then the coefficient of correlation = 0.8.

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Q 121Q 121

If X and Y are two variables with E(XY) = 10.56, E(X) = 4.22, and E(Y) = 5.34, then COV(X, Y) = 1.0.

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Q 122Q 122

If X and Y are two variables with

_{x}= 3.8, _{y}= 4.2, and COV(X, Y) = 0.25, then V(X + Y) = 31.58.Free

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Q 123Q 123

If you add two single probability distributions together you get a bivariate distribution.

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Q 124Q 124

The variance of X must be non-negative; the variance of Y must be non-negative; hence the covariance of X and Y must be non-negative.

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True False

Q 125Q 125

If X and Y are two variables with , , and COV(X, Y) = 14.703, then the coefficient of correlation = 0.78.

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Q 126Q 126

A statistical measure of the strength of the relationship between two random variables X and Y is referred to as the:
A) expected value
B) variance
C) covariance
D) standard deviation

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Q 127Q 127

If X and Y are random variables, the sum of all the conditional probabilities of X given a specific value of Y will always be:
A) 0.0
B) 1.0
C) the average of the possible values of X.
D) the average of the possible values of Y.

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Q 128Q 128

If X and Y are random variables with E(X) = 6 and E(Y) = 9, then E(2X + 3Y) is:
A) 39
B) 15
C) 27
D) 12

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Q 129Q 129

The covariance of two variables X and Y:
A) must be between 1 and +1.
B) must be positive.
C) can be any real number.
D) None of these choices.

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Q 130Q 130

If X and Y are any random variables with E(X) = 5, E(Y) = 6, E(XY) = 21, V(X) = 9 and V(Y) = 10, then the relationship between X and Y is a:
A) strong positive relationship
B) strong negative relationship
C) weak positive relationship
D) weak negative relationship

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Multiple Choice

Q 131Q 131

If X and Y are independent random variables, which of the following identities is false?
A) COV(X, Y) = 1
B) E(X + Y) = E(X) + E(Y)
C) V(X + Y) = V(X) + V(Y)
D) All of these choices are true.

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Q 132Q 132

A(n) ____________________ distribution provides probabilities of combinations of two random variables.

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Q 133Q 133

The ____________________ of X and Y is one measure of the strength and direction of the linear relationship between X and Y.However this number is hard to put into perspective.

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Q 134Q 134

The ____________________ of X and Y is a measure of the strength and direction of the linear relationship between X and Y.It is easy to put into perspective because it is always between 1 and 1.

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Q 135Q 135

The expected value of the sum of two random variables X and Y is equal to the ____________________ of the expected value of X and the expected value of Y.

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Q 136Q 136

If X and Y are ____________________, the variance of their sum is equal to the sum of their variances.

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Q 138Q 138

If X and Y are independent, then the coefficient of correlation equals ____________________.

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Q 139Q 139

In a bivariate distribution, the sum of all the ____________________ probabilities must equal 1.

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Q 140Q 140

A probability distribution for a single random variable is referred to as a(n) ____________________ distribution.

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Q 141Q 141

The ____________________ and the ____________________ both measure the relationship between two random variables X and Y.

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Q 142Q 142

Number of Birds
Alana and Eva are sisters.Let X denote the number of birds that Alana may have in the next two years, and let Y denote the number of birds Eva may have during the same period.The marginal probability distributions of X and Y are shown below.
-{Number of Birds Narrative} Compute the mean and variance of X.

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Essay

Q 143Q 143

Number of Birds
Alana and Eva are sisters.Let X denote the number of birds that Alana may have in the next two years, and let Y denote the number of birds Eva may have during the same period.The marginal probability distributions of X and Y are shown below.
-{Number of Birds Narrative} Compute the mean and variance of Y.

Free

Essay

Q 144Q 144

Number of Birds
Alana and Eva are sisters.Let X denote the number of birds that Alana may have in the next two years, and let Y denote the number of birds Eva may have during the same period.The marginal probability distributions of X and Y are shown below.
-{Number of Birds Narrative} Assume that X and Y are independent and find their bivariate distribution.

Free

Essay

Q 145Q 145

Number of Birds
Alana and Eva are sisters.Let X denote the number of birds that Alana may have in the next two years, and let Y denote the number of birds Eva may have during the same period.The marginal probability distributions of X and Y are shown below.
-{Number of Birds Narrative} Compute the covariance between X and Y.

Free

Essay

Q 146Q 146

Number of Birds
Alana and Eva are sisters.Let X denote the number of birds that Alana may have in the next two years, and let Y denote the number of birds Eva may have during the same period.The marginal probability distributions of X and Y are shown below.
-{Number of Birds Narrative} Compute the coefficient of correlation between X and Y.Did you expect this result? Why?

Free

Essay

Q 147Q 147

Number of Birds
Alana and Eva are sisters.Let X denote the number of birds that Alana may have in the next two years, and let Y denote the number of birds Eva may have during the same period.The marginal probability distributions of X and Y are shown below.
-{Number of Birds Narrative} Determine the probability distribution of the random variable X + Y.

Free

Essay

Q 148Q 148

Number of Birds
Alana and Eva are sisters.Let X denote the number of birds that Alana may have in the next two years, and let Y denote the number of birds Eva may have during the same period.The marginal probability distributions of X and Y are shown below.
-{Number of Birds Narrative} Calculate E(X + Y) directly by using the probability distribution of X + Y.

Free

Essay

Q 149Q 149

Number of Birds
Alana and Eva are sisters.Let X denote the number of birds that Alana may have in the next two years, and let Y denote the number of birds Eva may have during the same period.The marginal probability distributions of X and Y are shown below.
-{Number of Birds Narrative} Calculate V(X + Y) directly by using the probability distribution of X + Y.

Free

Essay

Q 150Q 150

Number of Birds
Alana and Eva are sisters.Let X denote the number of birds that Alana may have in the next two years, and let Y denote the number of birds Eva may have during the same period.The marginal probability distributions of X and Y are shown below.
-{Number of Birds Narrative} Verify that V(X + Y) = V(X) + V(Y).Did you expect this result? Why?

Free

Essay

Q 151Q 151

Number of Birds
Alana and Eva are sisters.Let X denote the number of birds that Alana may have in the next two years, and let Y denote the number of birds Eva may have during the same period.The marginal probability distributions of X and Y are shown below.
-{Number of Birds Narrative} Find the probability distribution of the random variable XY.

Free

Essay

Q 152Q 152

Number of Birds
Alana and Eva are sisters.Let X denote the number of birds that Alana may have in the next two years, and let Y denote the number of birds Eva may have during the same period.The marginal probability distributions of X and Y are shown below.
-{Number of Birds Narrative} Calculate E(XY) directly by using the probability distribution of XY.

Free

Essay

Q 153Q 153

Number of Birds
Alana and Eva are sisters.Let X denote the number of birds that Alana may have in the next two years, and let Y denote the number of birds Eva may have during the same period.The marginal probability distributions of X and Y are shown below.
-{Number of Birds Narrative} Verify that E(XY) = E(X)E(Y).Did you expect this result? Why?

Free

Essay

Q 154Q 154

Golfing Store
The joint probability distribution of variables X and Y is shown in the table below, where X is the number of drivers and Y is the number of putters sold daily in a small golfing store.
-{Golfing Store Narrative} Calculate E(XY).

Free

Essay

Q 155Q 155

Golfing Store
The joint probability distribution of variables X and Y is shown in the table below, where X is the number of drivers and Y is the number of putters sold daily in a small golfing store.
-{Golfing Store Narrative} Determine the marginal probability distributions of X and Y.

Free

Essay

Q 156Q 156

Golfing Store
The joint probability distribution of variables X and Y is shown in the table below, where X is the number of drivers and Y is the number of putters sold daily in a small golfing store.
-{Golfing Store Narrative} Are X and Y independent? Explain.

Free

Essay

Q 157Q 157

Golfing Store
The joint probability distribution of variables X and Y is shown in the table below, where X is the number of drivers and Y is the number of putters sold daily in a small golfing store.
-{Golfing Store Narrative} Find P(Y = 2 | X = 1)

Free

Essay

Q 158Q 158

Golfing Store
The joint probability distribution of variables X and Y is shown in the table below, where X is the number of drivers and Y is the number of putters sold daily in a small golfing store.
-{Golfing Store Narrative} Calculate the expected values of X and Y.

Free

Essay

Q 159Q 159

Golfing Store
The joint probability distribution of variables X and Y is shown in the table below, where X is the number of drivers and Y is the number of putters sold daily in a small golfing store.
-{Golfing Store Narrative} Calculate the variances of X and Y.

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Essay

Q 160Q 160

Golfing Store
The joint probability distribution of variables X and Y is shown in the table below, where X is the number of drivers and Y is the number of putters sold daily in a small golfing store.
-{Golfing Store Narrative} Calculate COV(X,Y).Did you expect this answer? Why?

Free

Essay

Q 161Q 161

Golfing Store
The joint probability distribution of variables X and Y is shown in the table below, where X is the number of drivers and Y is the number of putters sold daily in a small golfing store.
-{Golfing Store Narrative} Find the probability distribution of the random variable X + Y.

Free

Essay

Q 162Q 162

Golfing Store
The joint probability distribution of variables X and Y is shown in the table below, where X is the number of drivers and Y is the number of putters sold daily in a small golfing store.
-{Golfing Store Narrative} Calculate E(X + Y) and V(X + Y) directly by using the probability distribution of X + Y.

Free

Essay

Q 163Q 163

Golfing Store
The joint probability distribution of variables X and Y is shown in the table below, where X is the number of drivers and Y is the number of putters sold daily in a small golfing store.
-{Golfing Store Narrative} Verify that V(X + Y) = V(X) + V(Y).Did you expect this result? Why?

Free

Essay

Q 164Q 164

Number of Hamsters
The joint probability distribution of X and Y is shown in the accompanying table, where X denotes the number of hamsters that Quinn may have next year, and Y denotes the number of hamsters that her boyfriend, Jason, may have when she moves in with him next year.
-{Number of Hamsters Narrative} Calculate E(XY).

Free

Essay

Q 165Q 165

Number of Hamsters
The joint probability distribution of X and Y is shown in the accompanying table, where X denotes the number of hamsters that Quinn may have next year, and Y denotes the number of hamsters that her boyfriend, Jason, may have when she moves in with him next year.
-{Number of Hamsters Narrative} Determine the marginal probability distributions of X and Y.

Free

Essay

Q 166Q 166

Number of Hamsters
The joint probability distribution of X and Y is shown in the accompanying table, where X denotes the number of hamsters that Quinn may have next year, and Y denotes the number of hamsters that her boyfriend, Jason, may have when she moves in with him next year.
-{Number of Hamsters Narrative} Calculate all possible values of the conditional probabilities, for X given Y and for Y given X.

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Essay

Q 167Q 167

Number of Hamsters
The joint probability distribution of X and Y is shown in the accompanying table, where X denotes the number of hamsters that Quinn may have next year, and Y denotes the number of hamsters that her boyfriend, Jason, may have when she moves in with him next year.
-{Number of Hamsters Narrative} Are X and Y independent? Explain.

Free

Essay

Q 168Q 168

Number of Hamsters
The joint probability distribution of X and Y is shown in the accompanying table, where X denotes the number of hamsters that Quinn may have next year, and Y denotes the number of hamsters that her boyfriend, Jason, may have when she moves in with him next year.
-{Number of Hamsters Narrative} Compute the covariance and the coefficient of correlation.

Free

Essay

Q 169Q 169

Car Sales
The joint probability distribution of variables X and Y is shown in the table below.Rebecca and Rachel are car salespeople.Let X denote the number of cars that Rebecca will sell in a month, and let Y denote the number of cars Rachel will sell in a month.
-{Car Sales Narrative} Determine the marginal probability distribution of X.

Free

Essay

Q 170Q 170

Car Sales
The joint probability distribution of variables X and Y is shown in the table below.Rebecca and Rachel are car salespeople.Let X denote the number of cars that Rebecca will sell in a month, and let Y denote the number of cars Rachel will sell in a month.
-{Car Sales Narrative} Determine the marginal probability distribution of Y.

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Essay

Q 171Q 171

Car Sales
The joint probability distribution of variables X and Y is shown in the table below.Rebecca and Rachel are car salespeople.Let X denote the number of cars that Rebecca will sell in a month, and let Y denote the number of cars Rachel will sell in a month.
-{Car Sales Narrative} Calculate E(X) and E(Y).

Free

Essay

Q 172Q 172

Car Sales
The joint probability distribution of variables X and Y is shown in the table below.Rebecca and Rachel are car salespeople.Let X denote the number of cars that Rebecca will sell in a month, and let Y denote the number of cars Rachel will sell in a month.
-{Car Sales Narrative} Calculate V(X) and V(Y).

Free

Essay

Q 173Q 173

Car Sales
The joint probability distribution of variables X and Y is shown in the table below.Rebecca and Rachel are car salespeople.Let X denote the number of cars that Rebecca will sell in a month, and let Y denote the number of cars Rachel will sell in a month.
-{Car Sales Narrative} Develop the probability distribution of X + Y.

Free

Essay

Q 174Q 174

Car Sales
The joint probability distribution of variables X and Y is shown in the table below.Rebecca and Rachel are car salespeople.Let X denote the number of cars that Rebecca will sell in a month, and let Y denote the number of cars Rachel will sell in a month.
-{Car Sales Narrative} Calculate E(X + Y) directly by using the probability distribution of X + Y.

Free

Essay

Q 175Q 175

Car Sales
The joint probability distribution of variables X and Y is shown in the table below.Rebecca and Rachel are car salespeople.Let X denote the number of cars that Rebecca will sell in a month, and let Y denote the number of cars Rachel will sell in a month.
-{Car Sales Narrative} Calculate V(X + Y) directly by using the probability distribution of X + Y.

Free

Essay

Q 176Q 176

Car Sales
The joint probability distribution of variables X and Y is shown in the table below.Rebecca and Rachel are car salespeople.Let X denote the number of cars that Rebecca will sell in a month, and let Y denote the number of cars Rachel will sell in a month.
-{Car Sales Narrative} Verify that E(X + Y) = E(X) + E(Y).

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Essay

Q 177Q 177

Car Sales
The joint probability distribution of variables X and Y is shown in the table below.Rebecca and Rachel are car salespeople.Let X denote the number of cars that Rebecca will sell in a month, and let Y denote the number of cars Rachel will sell in a month.
-{Car Sales Narrative} Verify that V(X + Y) = V(X) + V(Y).Did you expect this result? Why?

Free

Essay

Q 178Q 178

Mobile Phones Sales
After analyzing sales data, the owner of a Mobile Phone store produced the following joint probability distribution of the number of iPhones (X) and Blackberries (Y) sold daily.
-{Mobile Phones Sales Narrative} Find the marginal probability distribution of the number of iPhones sold daily.

Free

Essay

Q 179Q 179

Mobile Phones Sales
After analyzing sales data, the owner of a Mobile Phone store produced the following joint probability distribution of the number of iPhones (X) and Blackberries (Y) sold daily.
-{Mobile Phones Sales Narrative} Compute the expected number of iPhones sold daily.

Free

Essay

Q 180Q 180

Mobile Phones Sales
After analyzing sales data, the owner of a Mobile Phone store produced the following joint probability distribution of the number of iPhones (X) and Blackberries (Y) sold daily.
-{Mobile Phones Sales Narrative} Compute the variance of the number of iPhones sold daily.

Free

Essay

Q 181Q 181

Mobile Phones Sales
After analyzing sales data, the owner of a Mobile Phone store produced the following joint probability distribution of the number of iPhones (X) and Blackberries (Y) sold daily.
-{Mobile Phones Sales Narrative} Find the marginal probability distribution of the number of Blackberries sold daily.

Free

Essay

Q 182Q 182

Mobile Phones Sales
After analyzing sales data, the owner of a Mobile Phone store produced the following joint probability distribution of the number of iPhones (X) and Blackberries (Y) sold daily.
-{Mobile Phones Sales Narrative} Find the marginal probability distribution of the number of Blackberries sold daily.

Free

Essay

Q 183Q 183

Mobile Phones Sales
After analyzing sales data, the owner of a Mobile Phone store produced the following joint probability distribution of the number of iPhones (X) and Blackberries (Y) sold daily.
-{Mobile Phones Sales Narrative} Compute the variance of the number of Blackberries sold daily.

Free

Essay

Q 184Q 184

Mobile Phones Sales
After analyzing sales data, the owner of a Mobile Phone store produced the following joint probability distribution of the number of iPhones (X) and Blackberries (Y) sold daily.
-{Mobile Phones Sales Narrative} Find the probability distribution of X + Y.

Free

Essay

Q 185Q 185

Mobile Phones Sales
After analyzing sales data, the owner of a Mobile Phone store produced the following joint probability distribution of the number of iPhones (X) and Blackberries (Y) sold daily.
-{Mobile Phones Sales Narrative} Calculate E(X + Y) directly by using the probability distribution of X + Y.

Free

Essay

Q 186Q 186

Mobile Phones Sales
After analyzing sales data, the owner of a Mobile Phone store produced the following joint probability distribution of the number of iPhones (X) and Blackberries (Y) sold daily.
-{Mobile Phones Sales Narrative} Calculate V(X + Y) directly by using the probability distribution of X + Y.

Free

Essay

Q 187Q 187

Mobile Phones Sales
After analyzing sales data, the owner of a Mobile Phone store produced the following joint probability distribution of the number of iPhones (X) and Blackberries (Y) sold daily.
-{Mobile Phones Sales Narrative} Compare V(X) + V(Y) to V(X + Y).What is your conclusion?

Free

Essay

Q 188Q 188

One of the ways in which financial analysts lower the risk that is associated with the stock market is through diversification.

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True False

Q 189Q 189

The expected return of a portfolio of two investments will be equal to the sum of the expected returns of the two investments plus twice the covariance between the investments.

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True False

Q 190Q 190

The expected return of a two-asset portfolio is equal to the product of the weight assigned to the first asset and the expected return of the first asset plus the product of the weight assigned to the second asset and the expected return of the second asset.

Free

True False

Q 191Q 191

A portfolio return, R

_{p}, of two stocks with individual returns, R_{1}and R_{2}, is, in general, given by R_{p}= R_{1}+ R_{2}.Free

True False

Q 192Q 192

A portfolio expected return E(R

_{p}) of 3 stocks with the quantities w_{1}= .40, w_{2}= .50, w_{3}= .10, E(R_{1}) = .10, E(R_{2}) = .15, and E(R_{3}) = .02 is equal to 0.117.Free

True False

Q 193Q 193

The covariance between two investments of a portfolio is equal to the sum of the variances of the investments.

Free

True False

Q 194Q 194

If the covariance between two investments of a portfolio is zero, the variance of the portfolio will be equal to the sum of the variances of the investments.

Free

True False

Q 195Q 195

The variance of a portfolio of two investments will be equal to the sum of the variances of the two investments plus twice the covariance between the investments.

Free

True False

Q 196Q 196

The variance of a portfolio of two investments will be equal to the sum of the variances of the two investments when the covariance between the investments is zero.

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True False

Q 197Q 197

The portfolio expected return of two investments:
A) will be higher when the covariance is zero.
B) will be higher when the covariance is negative.
C) will be higher when the covariance is positive.
D) does not depend on the covariance.

Free

Multiple Choice

Q 198Q 198

The following information regarding a portfolio of two stocks are given: w

_{1}= .65, w_{2}= .35, E(R_{1}) = .12, and E(R_{2}) = .14.Which of the following regarding the portfolio expected return, E(R_{p}), is correct? A) .260 B) .127 C) .346 D) .374Free

Multiple Choice

Q 199Q 199

The following information regarding a portfolio of two stocks are given: w

_{1}= .25, w_{2}= .75, E(R_{1}) = .08, and E(R_{2}) = .15.Which of the following regarding the portfolio expected return, E(R_{p}), is correct? A) .3640 B) .2300 C) .1325 D) .1699Free

Multiple Choice

Q 200Q 200

Returns on Investment
An analysis of the stock market produces the following information about the returns of two stocks.
Assume that the returns are positively correlated with correlation coefficient of 0.80.
-{Returns on Investment Narrative} Find the mean of the return on a portfolio consisting of an equal investment in each of the two stocks.

Free

Essay

Q 201Q 201

Returns on Investment
An analysis of the stock market produces the following information about the returns of two stocks.
Assume that the returns are positively correlated with correlation coefficient of 0.80.
-{Returns on Investment Narrative} Find the standard deviation of the return on a portfolio consisting of an equal investment in each of the two stocks.

Free

Essay

Q 202Q 202

Returns on Investment
An analysis of the stock market produces the following information about the returns of two stocks.
Assume that the returns are positively correlated with correlation coefficient of 0.80.
-{Returns on Investment Narrative} Suppose that you wish to invest $1 million.Discuss whether you should invest your money in stock 1, stock 2, or a portfolio composed of an equal amount of investments on both stocks.

Free

Essay

Q 203Q 203

Risky Undertaking
Suppose you make a $2,000 investment in a risky undertaking.There is a 50% chance that the payoff from the investment will be $5,000, a 20% chance that you will just get your money back, and a 30% chance that you will receive nothing at all from your investment.
-{Risky Undertaking Narrative} Find the expected value of the payoff from your investment of $2,000.

Free

Essay

Q 204Q 204

Risky Undertaking
Suppose you make a $2,000 investment in a risky undertaking.There is a 50% chance that the payoff from the investment will be $5,000, a 20% chance that you will just get your money back, and a 30% chance that you will receive nothing at all from your investment.
-{Risky Undertaking Narrative} Find the expected value of the net profit from your investment of $2,000.

Free

Essay

Q 205Q 205

Risky Undertaking
Suppose you make a $2,000 investment in a risky undertaking.There is a 50% chance that the payoff from the investment will be $5,000, a 20% chance that you will just get your money back, and a 30% chance that you will receive nothing at all from your investment.
-{Risky Undertaking Narrative} If you invest $6,000 in the risky undertaking instead of $2,000 and the possible payoffs triple accordingly, what are the expected value of the net profit from the $6,000 investment?

Free

Essay

Q 206Q 206

Elizabeth's Portfolio
Elizabeth has decided to form a portfolio by putting 30% of her money into stock 1 and 70% into stock 2.She assumes that the expected returns will be 10% and 18%, respectively, and that the standard deviations will be 15% and 24%, respectively.
-{Elizabeth's Portfolio Narrative} Find the expected mean of the portfolio.

Free

Essay

Q 207Q 207

Elizabeth's Portfolio
Elizabeth has decided to form a portfolio by putting 30% of her money into stock 1 and 70% into stock 2.She assumes that the expected returns will be 10% and 18%, respectively, and that the standard deviations will be 15% and 24%, respectively.
-{Elizabeth's Portfolio Narrative} Compute the standard deviation of the returns on the portfolio assuming that the two stocks' returns are perfectly positively correlated.

Free

Essay

Q 208Q 208

Elizabeth's Portfolio
Elizabeth has decided to form a portfolio by putting 30% of her money into stock 1 and 70% into stock 2.She assumes that the expected returns will be 10% and 18%, respectively, and that the standard deviations will be 15% and 24%, respectively.
-{Elizabeth's Portfolio Narrative} Compute the standard deviation of the returns on the portfolio assuming that the coefficient of correlation is 0.5.

Free

Essay

Q 209Q 209

Elizabeth's Portfolio
Elizabeth has decided to form a portfolio by putting 30% of her money into stock 1 and 70% into stock 2.She assumes that the expected returns will be 10% and 18%, respectively, and that the standard deviations will be 15% and 24%, respectively.
-{Elizabeth's Portfolio Narrative} Compute the standard deviation of the returns on the portfolio assuming that the two stocks' returns are uncorrelated.

Free

Essay

Q 210Q 210

Elizabeth's Portfolio
Elizabeth has decided to form a portfolio by putting 30% of her money into stock 1 and 70% into stock 2.She assumes that the expected returns will be 10% and 18%, respectively, and that the standard deviations will be 15% and 24%, respectively.
-{Elizabeth's Portfolio Narrative} Describe what happens to the standard deviation of the portfolio returns when the coefficient of correlation decreases.

Free

Essay

Q 211Q 211

Katie's Portfolio
Katie is given the following information about the returns on two stocks:
E(R

_{1}) = 0.10, E(R_{2}) = 0.15, V(R_{1}) = 0.0225, and V(R_{2}) = 0.0441. -{Katie's Portfolio Narrative} If Katie is most interested in maximizing her returns, which stock should she choose?Free

Essay

Q 212Q 212

Katie's Portfolio
Katie is given the following information about the returns on two stocks:
E(R

_{1}) = 0.10, E(R_{2}) = 0.15, V(R_{1}) = 0.0225, and V(R_{2}) = 0.0441. -{Katie's Portfolio Narrative} If Katie is most interested in minimizing her risk, which stock should she choose?Free

Essay

Q 213Q 213

Katie's Portfolio
Katie is given the following information about the returns on two stocks:
E(R

_{1}) = 0.10, E(R_{2}) = 0.15, V(R_{1}) = 0.0225, and V(R_{2}) = 0.0441. -{Katie's Portfolio Narrative} Compute the expected value of the portfolio composed of 60% stock 1 and 40% stock 2.Free

Essay

Q 214Q 214

Katie's Portfolio
Katie is given the following information about the returns on two stocks:
E(R

_{1}) = 0.10, E(R_{2}) = 0.15, V(R_{1}) = 0.0225, and V(R_{2}) = 0.0441. -{Katie's Portfolio Narrative} Compute the variance of the portfolio composed of 60% stock 1, and 40% stock 2, if the coefficient of correlation is 0.40.Free

Essay

Q 215Q 215

Katie's Portfolio
Katie is given the following information about the returns on two stocks:
E(R

_{1}) = 0.10, E(R_{2}) = 0.15, V(R_{1}) = 0.0225, and V(R_{2}) = 0.0441. -{Katie's Portfolio Narrative} Compute the expected value of the portfolio composed of 30% stock 1 and 70% stock 2.Free

Essay

Q 216Q 216

Katie's Portfolio
Katie is given the following information about the returns on two stocks:
E(R

_{1}) = 0.10, E(R_{2}) = 0.15, V(R_{1}) = 0.0225, and V(R_{2}) = 0.0441. -{Katie's Portfolio Narrative} Compute the variance of the portfolio composed of 30% stock 1 and 70% stock 2, if the coefficient of correlation is 0.40.Free

Essay

Q 217Q 217

The binomial random variable is the number of successes that occur in a fixed period of time.

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True False

Free

True False

Q 219Q 219

The binomial distribution deals with consecutive trials, each of which has two possible outcomes.

Free

True False

Q 220Q 220

The number of customers arriving at a department store in a 5-minute period has a binomial distribution.

Free

True False

Free

True False

Free

True False

Free

True False

Q 224Q 224

The standard deviation of a binomial random variable X is given by the formula

^{}= np(1 p), where n is the number of trials, and p is the probability of success.Free

True False

Q 225Q 225

The number of female customers out of a random sample of 100 customers arriving at a department store has a binomial distribution.

Free

True False

Q 226Q 226

If the probability of success p remains constant in a binomial distribution, an increase in n will increase the variance.

Free

True False

Q 227Q 227

If the probability of success p remains constant in a binomial distribution, an increase in n will not change the mean.

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True False

Q 228Q 228

Which of the following about the binomial distribution is not a true statement?
A) The probability of success must be constant from trial to trial.
B) The random variable of interest is continuous.
C) Each outcome may be classified as either "success" or "failure".
D) Each outcome is independent of the other.

Free

Multiple Choice

Q 229Q 229

The expected number of heads in 100 tosses of an unbiased coin is
A) 25
B) 50
C) 75
D) 100

Free

Multiple Choice

Q 230Q 230

Which of the following is not a characteristic of a binomial experiment?
A) Each trial results in two or more outcomes.
B) There is a sequence of identical trials.
C) The trials are independent of each other.
D) The probability of success p is the same from one trial to another.

Free

Multiple Choice

Q 231Q 231

The variance of a binomial distribution for which n = 100 and p = 0.20 is:
A) 100
B) 80
C) 20
D) 16

Free

Multiple Choice

Q 232Q 232

If n = 10 and p = 0.60, then the mean of the binomial distribution is
A) 0.06
B) 2.65
C) 6.00
D) 5.76

Free

Multiple Choice

Q 233Q 233

If n = 20 and p = 0.70, then the standard deviation of the binomial distribution is
A) 0.14
B) 2.05
C) 14.0
D) 14.7

Free

Multiple Choice

Q 234Q 234

The expected value, E(X), of a binomial probability distribution with n trials and probability p of success is:
A) n + p
B) np(1 p)
C) np
D) n + p 1

Free

Multiple Choice

Free

Essay

Free

Essay

Free

Essay

Free

Essay

Q 239Q 239

The trials in a binomial experiment are ____________________, meaning the outcome of one trial does not affect the outcomes of any other trials.

Free

Essay

Free

Essay

Free

Essay

Q 242Q 242

The probability P(X x) is called a(n) ____________________ probability.The binomial table reports these probabilities.

Free

Essay

Q 243Q 243

To find the probability that X is at least 10, you should find the probability that X is 10 or ____________________.

Free

Essay

Q 244Q 244

To find the probability that X is at most 10, you should find the probability that X is 10 or ____________________.

Free

Essay

Q 245Q 245

Stress
Consider a binomial random variable X with n = 5 and p = 0.40, where X represents the number of times in the final exam week a student with 18 credit hours may feel stressed.
-{Stress Narrative} Find the probability distribution of X.

Free

Essay

Q 246Q 246

Stress
Consider a binomial random variable X with n = 5 and p = 0.40, where X represents the number of times in the final exam week a student with 18 credit hours may feel stressed.
-{Stress Narrative} Find P(X < 3).

Free

Essay

Q 247Q 247

Stress
Consider a binomial random variable X with n = 5 and p = 0.40, where X represents the number of times in the final exam week a student with 18 credit hours may feel stressed.
-{Stress Narrative} Find P(2 X 4).

Free

Essay

Q 248Q 248

Stress
Consider a binomial random variable X with n = 5 and p = 0.40, where X represents the number of times in the final exam week a student with 18 credit hours may feel stressed.
-{Stress Narrative} Find the expected number of times a student may feel stressed during the final exam week.

Free

Essay

Q 249Q 249

Stress
Consider a binomial random variable X with n = 5 and p = 0.40, where X represents the number of times in the final exam week a student with 18 credit hours may feel stressed.
-{Stress Narrative} Find the variance and standard deviation.

Free

Essay

Q 250Q 250

Montana Highways
A recent survey in Montana revealed that 60% of the vehicles traveling on highways, where speed limits are posted at 70 miles per hour, were exceeding the limit.Suppose you randomly record the speeds of ten vehicles traveling on US 131 where the speed limit is 70 miles per hour.Let X denote the number of vehicles that were exceeding the limit.
-{Montana Highways Narrative} What is the distribution of X?

Free

Essay

Q 251Q 251

Montana Highways
A recent survey in Montana revealed that 60% of the vehicles traveling on highways, where speed limits are posted at 70 miles per hour, were exceeding the limit.Suppose you randomly record the speeds of ten vehicles traveling on US 131 where the speed limit is 70 miles per hour.Let X denote the number of vehicles that were exceeding the limit.
-{Montana Highways Narrative} Find P(X = 10).

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Q 252Q 252

Montana Highways
A recent survey in Montana revealed that 60% of the vehicles traveling on highways, where speed limits are posted at 70 miles per hour, were exceeding the limit.Suppose you randomly record the speeds of ten vehicles traveling on US 131 where the speed limit is 70 miles per hour.Let X denote the number of vehicles that were exceeding the limit.
-{Montana Highways Narrative} Find P(4 < X < 9).

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Q 253Q 253

Montana Highways
A recent survey in Montana revealed that 60% of the vehicles traveling on highways, where speed limits are posted at 70 miles per hour, were exceeding the limit.Suppose you randomly record the speeds of ten vehicles traveling on US 131 where the speed limit is 70 miles per hour.Let X denote the number of vehicles that were exceeding the limit.
-{Montana Highways Narrative} Find P(X = 2).

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Essay

Q 254Q 254

Montana Highways
A recent survey in Montana revealed that 60% of the vehicles traveling on highways, where speed limits are posted at 70 miles per hour, were exceeding the limit.Suppose you randomly record the speeds of ten vehicles traveling on US 131 where the speed limit is 70 miles per hour.Let X denote the number of vehicles that were exceeding the limit.
-{Montana Highways Narrative} Find P(3 X 6).

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Essay

Q 255Q 255

Montana Highways
A recent survey in Montana revealed that 60% of the vehicles traveling on highways, where speed limits are posted at 70 miles per hour, were exceeding the limit.Suppose you randomly record the speeds of ten vehicles traveling on US 131 where the speed limit is 70 miles per hour.Let X denote the number of vehicles that were exceeding the limit.
-{Montana Highways Narrative} Find the expected number of vehicles that are traveling on Montana highways and exceeding the speed limit.

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Essay

Q 256Q 256

Montana Highways
A recent survey in Montana revealed that 60% of the vehicles traveling on highways, where speed limits are posted at 70 miles per hour, were exceeding the limit.Suppose you randomly record the speeds of ten vehicles traveling on US 131 where the speed limit is 70 miles per hour.Let X denote the number of vehicles that were exceeding the limit.
-{Montana Highways Narrative} Find the standard deviation of number of vehicles that are traveling on Montana highways and exceeding the speed limit.

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Essay

Q 257Q 257

Online Bankers
An official from the securities commission estimates that 75% of all online bankers have profited from the use of insider information.Assume that 15 online bankers are selected at random from the commission's registry.
-{Online Bankers Narrative} Find the probability that at most 10 have profited from insider information.

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Q 258Q 258

Online Bankers
An official from the securities commission estimates that 75% of all online bankers have profited from the use of insider information.Assume that 15 online bankers are selected at random from the commission's registry.
-{Online Bankers Narrative} Find the probability that at least 6 have profited from insider information.

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Q 259Q 259

Online Bankers
An official from the securities commission estimates that 75% of all online bankers have profited from the use of insider information.Assume that 15 online bankers are selected at random from the commission's registry.
-{Online Bankers Narrative} Find the probability that all 15 have profited from insider information.

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Q 260Q 260

Online Bankers
An official from the securities commission estimates that 75% of all online bankers have profited from the use of insider information.Assume that 15 online bankers are selected at random from the commission's registry.
-{Online Bankers Narrative} What is the expected number of Online bankers who have profited from the use of insider information?

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Q 261Q 261

Online Bankers
An official from the securities commission estimates that 75% of all online bankers have profited from the use of insider information.Assume that 15 online bankers are selected at random from the commission's registry.
-{Online Bankers Narrative} Find the variance and standard deviation of the number of Online bankers who have profited from the use of insider information.

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Q 262Q 262

Let X be a binomial random variable with n = 25 and p = 0.01.
a.
Use the binomial table to find P(X = 0), P(X = 1), and P(X = 2).
b.
Find the variance and standard deviation of X.

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Q 263Q 263

A remedial program evenly enrolls tradition and non-traditional students.If a random sample of 4 students is selected from the program to be interviewed about the introduction of a new on-line class, what is the probability that all 4 students selected are traditional students?

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Q 266Q 266

If X has a binomial distribution with n = 4 and p = 0.3, find the probability that X is at most one.

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Q 267Q 267

If X has a binomial distribution with n = 4 and p = 0.3, find the probability that X is at least one.

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Q 268Q 268

Sports Fans
Suppose that past history shows that 5% of college students are sports fans.A sample of 10 students is to be selected.
-{Sports Fans Narrative} Find the probability that exactly 1 student is a sports fan.

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Q 269Q 269

Sports Fans
Suppose that past history shows that 5% of college students are sports fans.A sample of 10 students is to be selected.
-{Sports Fans Narrative} Find the probability that at least 1 student is a sports fan.

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Q 270Q 270

Sports Fans
Suppose that past history shows that 5% of college students are sports fans.A sample of 10 students is to be selected.
-{Sports Fans Narrative} Find the probability that less than 1 student is a sports fan.

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Q 271Q 271

Sports Fans
Suppose that past history shows that 5% of college students are sports fans.A sample of 10 students is to be selected.
-{Sports Fans Narrative} Find the probability that at most 1 student is a sports fan.

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Q 272Q 272

Sports Fans
Suppose that past history shows that 5% of college students are sports fans.A sample of 10 students is to be selected.
-{Sports Fans Narrative} Find the probability that more than 1 student is a sports fan.

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Q 273Q 273

Sports Fans
Suppose that past history shows that 5% of college students are sports fans.A sample of 10 students is to be selected.
-{Sports Fans Narrative} A sample of 100 students is to be selected.What is the average number that you would expect to sports fan?

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Q 274Q 274

Sports Fans
Suppose that past history shows that 5% of college students are sports fans.A sample of 10 students is to be selected.
-{Sports Fans Narrative} A sample of 100 students is to be selected.What is the standard deviation of the number of sports fans you expect?

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