Question 1

A set of final examination grades in a calculus course was found to be normally distributed with a mean of 69 and a standard deviation of 9.
-What percentage of students scored between 81 and 89?

Accepted Answer

The answer of A set of final examination grades in...

Question 2

Suppose that the waiting time for a pizza to be delivered to an individual's residence has been found to be normally distributed with a mean of 30 minutes and a standard deviation of 8 minutes. What is the probability that a randomly selected individual will have a waiting time
-Between 15 and 45 minutes

Accepted Answer

The answer of Suppose that the waiting time for a...

Question 3

During the past six months, 73.2% of households purchased sugar. Assume that these expenditures are approximately normally distributed with a mean of $8.22 and a standard deviation of $1.10.
-What proportion of the households spent between $5.00 and $9.00?

Accepted Answer

The answer of During the past six months, 73.2% of...

Question 4

At a Great Lakes nuclear power plant, lake water is used as part of the cooling system. This raises the temperature of the water that is discharged back into the lake. The amount that the water temperature is raised has a uniform distribution over the interval from 10 to 25º C.
-What is the expected value of the temperature increase?

Accepted Answer

The answer of At a Great Lakes nuclear power plant,...

Question 5

At a Great Lakes nuclear power plant, lake water is used as part of the cooling system. This raises the temperature of the water that is discharged back into the lake. The amount that the water temperature is raised has a uniform distribution over the interval from 10 to 25º C.
-What is the standard deviation of the temperature increase?

Accepted Answer

The answer of At a Great Lakes nuclear power plant,...

Question 6

During the past six months, 73.2% of households purchased sugar. Assume that these expenditures are approximately normally distributed with a mean of $8.22 and a standard deviation of $1.10.
-Find the probability that a household spent more than $10.00

Accepted Answer

The answer of During the past six months, 73.2% of...

Question 7

During the past six months, 73.2% of households purchased sugar. Assume that these expenditures are approximately normally distributed with a mean of $8.22 and a standard deviation of $1.10.
-Find the probability that a household spent more than $16.00

Accepted Answer

The answer of During the past six months, 73.2% of...

Question 8

Suppose that the times required for a cable company to fix cable problems in its customers' homes are uniformly distributed between 40 minutes and 65 minutes
-What is the probability that a randomly selected cable repair visit will take at least 50 minutes?

Accepted Answer

The answer of Suppose that the times required for a...

Question 9

What is the probability that a randomly selected cable repair visit falls within 2 standard deviations of the mean?

Accepted Answer

The answer of What is the probability that a randomly...

Question 10

During the past six months, 73.2% of households purchased sugar. Assume that these expenditures are approximately normally distributed with a mean of $8.22 and a standard deviation of $1.10.
-Find the probability that a household spent less than $5.00

Accepted Answer

The answer of During the past six months, 73.2% of...

Question 11

While conducting experiments, a marine biologist selects water depths from a uniformly distributed collection that vary between 2.00 m and 7.00 m.
-What is the probability that a randomly selected depth is between 2.25 m and 5.00 m?

Accepted Answer

The answer of While conducting experiments, a marine biologist selects...

Question 12

A manufacturer of personal computers sets tests competing brands and finds that the amounts of energy they require are normally distributed with a mean of 285 kwh and a standard deviation of 9.1 kwh.
If the lowest 25% and the highest 30% are not included in a second round of tests,what are the upper and lower limits for the energy amounts of the remaining sets?

Accepted Answer

The answer of A manufacturer of personal computers sets tests...

Question 13

A set of final examination grades in a calculus course was found to be normally distributed with a mean of 69 and a standard deviation of 9.
-What percentage of students scored between 65 and 89?

Accepted Answer

The answer of A set of final examination grades in...

Question 14

Suppose that in an effort to provide better service to the public,the manager of the pizza delivery service is permitted to provide discounts to those individuals whose waiting time exceeds a predetermined time.The director decides that 15% of the customers should receive this discount.What are the number of minutes they need to wait to receive the discount?

Accepted Answer

The answer of Suppose that in an effort to provide...

Question 15

While conducting experiments, a marine biologist selects water depths from a uniformly distributed collection that vary between 2.00 m and 7.00 m.
-What is the probability that a randomly selected depth is less than 3.60 m?

Accepted Answer

The answer of While conducting experiments, a marine biologist selects...

Question 16

Complete the following statement: Only 20% of the individuals wait less than _____ minutes.

Accepted Answer

The answer of Complete the following statement: Only 20% of...

Question 17

A set of final examination grades in a calculus course was found to be normally distributed with a mean of 69 and a standard deviation of 9.
-What is the probability of getting a grade of 91 or less on this exam?

Accepted Answer

The answer of A set of final examination grades in...

Question 18

Suppose that the waiting time for a pizza to be delivered to an individual's residence has been found to be normally distributed with a mean of 30 minutes and a standard deviation of 8 minutes. What is the probability that a randomly selected individual will have a waiting time
-No more than 22 minutes

Accepted Answer

The answer of Suppose that the waiting time for a...

Question 19

Suppose that the waiting time for a pizza to be delivered to an individual's residence has been found to be normally distributed with a mean of 30 minutes and a standard deviation of 8 minutes. What is the probability that a randomly selected individual will have a waiting time
-At least 10 minutes

Accepted Answer

The answer of Suppose that the waiting time for a...

Question 20

A set of final examination grades in a calculus course was found to be normally distributed with a mean of 69 and a standard deviation of 9.
-Only 5% of the students taking the test scored higher than what grade?

Accepted Answer

The answer of A set of final examination grades in...

Quiz 5: Continuous Random Variables

A set of final examination grades in a calculus course was found to be normally distributed with a mean of 69 and a standard deviation of 9. -What percentage of students scored between 81 and 89?

During the past six months, 73.2% of households purchased sugar. Assume that these expenditures are approximately normally distributed with a mean of $8.22 and a standard deviation of $1.10. -What proportion of the households spent between $5.00 and $9.00?

During the past six months, 73.2% of households purchased sugar. Assume that these expenditures are approximately normally distributed with a mean of $8.22 and a standard deviation of $1.10. -Find the probability that a household spent more than $10.00

During the past six months, 73.2% of households purchased sugar. Assume that these expenditures are approximately normally distributed with a mean of $8.22 and a standard deviation of $1.10. -Find the probability that a household spent more than $16.00

Suppose that the times required for a cable company to fix cable problems in its customers' homes are uniformly distributed between 40 minutes and 65 minutes -What is the probability that a randomly selected cable repair visit will take at least 50 minutes?

What is the probability that a randomly selected cable repair visit falls within 2 standard deviations of the mean?

During the past six months, 73.2% of households purchased sugar. Assume that these expenditures are approximately normally distributed with a mean of $8.22 and a standard deviation of $1.10. -Find the probability that a household spent less than $5.00

While conducting experiments, a marine biologist selects water depths from a uniformly distributed collection that vary between 2.00 m and 7.00 m. -What is the probability that a randomly selected depth is between 2.25 m and 5.00 m?

A set of final examination grades in a calculus course was found to be normally distributed with a mean of 69 and a standard deviation of 9. -What percentage of students scored between 65 and 89?

While conducting experiments, a marine biologist selects water depths from a uniformly distributed collection that vary between 2.00 m and 7.00 m. -What is the probability that a randomly selected depth is less than 3.60 m?

Complete the following statement: Only 20% of the individuals wait less than _____ minutes.

A set of final examination grades in a calculus course was found to be normally distributed with a mean of 69 and a standard deviation of 9. -What is the probability of getting a grade of 91 or less on this exam?

Suppose that the waiting time for a pizza to be delivered to an individual's residence has been found to be normally distributed with a mean of 30 minutes and a standard deviation of 8 minutes. What is the probability that a randomly selected individual will have a waiting time -At least 10 minutes

A set of final examination grades in a calculus course was found to be normally distributed with a mean of 69 and a standard deviation of 9. -Only 5% of the students taking the test scored higher than what grade?