Question 1

Suppose that 10 golfers enter a tournament and that their respective skill levels are approximately the same.Six of the entrants are female and two of those are older than 40 years old.Three of the men are older than 40 years old.What is the probability that the winner will be a female who is older than 40 years old?

Accepted Answer

There are 10 golfers in total, and 2 of them are females older than 40. The probability that one of these 2 females wins is 2/10, which simplifies to 0.200.

Question 2

"The probability of event B,given that event A has occurred" is known as a ________ probability.

Accepted Answer

The given statement describes the concept of conditional probability where the event B is dependent on the occurrence of event A. Therefore, the best choice is E) conditional probability.

Question 3

A conditional probability P(B|A)is equal to its marginal probability P(B)if

Accepted Answer

If events A and B are statistically independent, meaning that the occurrence of one event does not affect the probability of the other event occurring, then P(B|A) = P(B).

Question 4

A consulting firm has received 2 Super Bowl playoff tickets from one of its clients.To be fair,the firm is randomly selecting two different employee names to "win" the tickets.There are 6 secretaries,5 consultants,and 4 partners in the firm.Which of the following statements is true?

Accepted Answer

The answer of A consulting firm has received 2 Super...

Question 5

Bayes' theorem is used to calculate

Accepted Answer

Bayes' theorem is used to update or revise a prior probability based on new evidence or information. Therefore, the correct answer is revised probabilities (A). The formula for Bayes' theorem involves calculating the probability of an event given that another event has occurred, using the prior probability and the conditional probability.

Question 6

A consulting firm has received 2 Super Bowl playoff tickets from one of its clients.To be fair,the firm is randomly selecting two different employee names to "win" the tickets.There are 6 secretaries,5 consultants,and 4 partners in the firm.Which of the following statements is true?

Accepted Answer

If a partner wins on the first draw, there are now 3 partners left out of a total of 13 remaining employees. Therefore, the probability of a partner winning on the second draw is 3/13, which simplifies to 3/14 when considering the initial condition.

Question 7

A consulting firm has received 2 Super Bowl playoff tickets from one of its clients.To be fair,the firm is randomly selecting two different employee names to "win" the tickets.There are 6 secretaries,5 consultants and 4 partners in the firm.Which of the following statements is not true?

Accepted Answer

The probability of a secretary winning a ticket on the second draw given that a consultant won the first draw is 6/14, not 6/15, because one person has already been drawn, leaving 14 people.

Question 8

Assume you have a normal distribution representing the likelihood of completion times.The mean of this distribution is 10,and the standard deviation is 3.The probability of completing the project in 7 or fewer days is the same as the probability of completing the project in 13 days or more.

Accepted Answer

In a normal distribution, the probabilities on either side of the mean at equal distances are the same. Since 7 is 3 units below the mean (10) and 13 is 3 units above the mean, the probabilities of completion times less than 7 days and more than 13 days are equal.

Question 9

Subjective probability assessments depend on

Accepted Answer

Subjective probability assessments rely on personal experience and judgment, rather than objective measures such as total number of trials or frequency of occurrence. It is based on an individual's own perception and estimation of the likelihood of an event occurring.

Question 10

Suppose that we determine the probability of a warm winter based on the number of warm winters experienced over the past 10 years.In this case,we have used

Accepted Answer

We have used relative frequency, which is a method of determining probability based on the number of times an event has occurred compared to the total number of opportunities for the event to occur.

Question 11

When does P(A|B)= P(A)?

Accepted Answer

If A and B are statistically independent, then the occurrence of event B does not affect the probability of event A. Therefore, P(A|B) = P(A).

Question 12

A ________ is a numerical statement about the likelihood that an event will occur.

Accepted Answer

A probability is a numerical statement about the likelihood that an event will occur. The other choices do not fit the definition of a statement about the likelihood of an event.

Question 13

If the sale of ice cream and pizza are independent,then as ice cream sales decrease by 60 percent during the winter months,pizza sales will

Accepted Answer

The independence of ice cream and pizza sales means that the two events have no effect on each other. Therefore, the decrease in ice cream sales has no impact on pizza sales, and they remain unrelated.

Question 14

The equation P(A|B)= P(AB)/P(B)is

Accepted Answer

This equation represents the formula for a conditional probability, where the probability of event A given event B has occurred is equal to the probability of both events A and B occurring (joint probability) divided by the probability of event B occurring (marginal probability of event B).

Question 15

Suppose that 10 golfers enter a tournament and that their respective skill levels are approximately the same.What is the probability that one of the first three golfers that registered for the tournament will win?

Accepted Answer

Since all golfers have approximately the same skill level, each golfer has an equal chance of winning the tournament. The probability of one of the first three golfers winning is simply the probability that any one of those three golfers wins, which is 3/10. Therefore, the probability is 0.3.

Question 16

At a university with 1,000 business majors,there are 200 business students enrolled in an introductory statistics course.Of these 200 students,50 are also enrolled in an introductory accounting course.There are an additional 250 business students enrolled in accounting but not enrolled in statistics.If a business student is selected at random,what is the probability that the student is either enrolled in accounting or statistics,but not both?

Accepted Answer

To find the probability that a business student is enrolled in either accounting or statistics, but not both, we need to subtract the probability of being enrolled in both courses from the total probability of being enrolled in either course. 
Total probability of being enrolled in either course = (200 + 250)/1000 = 0.45
Probability of being enrolled in both courses = 50/1000 = 0.05
Therefore, the probability of being enrolled in either course but not both = 0.45 - 0.05 = 0.40. Hence, the best choice is C.

Question 17

The classical method of determining probability is

Accepted Answer

The classical method of determining probability is based on the assumption of equally likely outcomes, making it an objective approach to probability.

Question 18

The F statistic is the ratio of two sample standard deviations from independent normal distributions.

Accepted Answer

The F statistic is actually the ratio of two sample variances, not standard deviations. Furthermore, the distributions do not have to be normal for the F statistic to be used in certain statistical tests.

Question 19

If two events are mutually exclusive,then

Accepted Answer

Mutually exclusive events cannot occur simultaneously, so their joint probability is 0. Their probabilities can be added, and they may also be collectively exhaustive if they cover all possible outcomes.

Question 20

Suppose that 10 golfers enter a tournament and that their respective skill levels are approximately the same.Six of the entrants are female and two of those are older than 40 years old.Three of the men are older than 40 years old.What is the probability that the winner will be either female or older than 40 years old?

Accepted Answer

There are 10 golfers in total. The probability of the winner being female is 6/10. The probability of the winner being older than 40 is (2 females + 3 males)/10 = 5/10. Using the principle of inclusion-exclusion, the probability of the winner being either female or older than 40 is (6/10) + (5/10) - (2/10) = 9/10 = 0.900.

Quiz 2: Probability Concepts and Applications

"The probability of event B,given that event A has occurred" is known as a ________ probability.

A conditional probability P(B|A) is equal to its marginal probability P(B) if

A consulting firm has received 2 Super Bowl playoff tickets from one of its clients.To be fair,the firm is randomly selecting two different employee names to "win" the tickets.There are 6 secretaries,5 consultants,and 4 partners in the firm.Which of the following statements is true?

Bayes' theorem is used to calculate

A consulting firm has received 2 Super Bowl playoff tickets from one of its clients.To be fair,the firm is randomly selecting two different employee names to "win" the tickets.There are 6 secretaries,5 consultants,and 4 partners in the firm.Which of the following statements is true?

A consulting firm has received 2 Super Bowl playoff tickets from one of its clients.To be fair,the firm is randomly selecting two different employee names to "win" the tickets.There are 6 secretaries,5 consultants and 4 partners in the firm.Which of the following statements is not true?

Assume you have a normal distribution representing the likelihood of completion times.The mean of this distribution is 10,and the standard deviation is 3.The probability of completing the project in 7 or fewer days is the same as the probability of completing the project in 13 days or more.

Subjective probability assessments depend on

Suppose that we determine the probability of a warm winter based on the number of warm winters experienced over the past 10 years.In this case,we have used

When does P(A|B) = P(A) ?

A ________ is a numerical statement about the likelihood that an event will occur.

If the sale of ice cream and pizza are independent,then as ice cream sales decrease by 60 percent during the winter months,pizza sales will

The equation P(A|B) = P(AB) /P(B) is

Suppose that 10 golfers enter a tournament and that their respective skill levels are approximately the same.What is the probability that one of the first three golfers that registered for the tournament will win?

The classical method of determining probability is

The F statistic is the ratio of two sample standard deviations from independent normal distributions.

If two events are mutually exclusive,then