5. The following probability distributions of job satisfaction scores for a sample of information systems (IS) senior executives and middle managers range from a low of 1 (very dissatisfied) to a high of 5 (very satisfied).

Job Satisfaction Score	Probability
IS Senior Executives	IS Middle Managers
1	0.05	0.04
2	0.09	0.10
3	0.03	0.13
4	0.42	0.47
5	0.41	0.26

(a)

What is the expected value of the job satisfaction score for senior executives?

(b)

What is the expected value of the job satisfaction score for middle managers?

(c)

Compute the variance of job satisfaction scores for executives and middle managers.

executivesmiddle managers

(d)

Compute the standard deviation of job satisfaction scores for both probability distributions. (Round your answers to two decimal places.)

executivesmiddle managers

(e)

Compare the overall job satisfaction of senior executives and middle managers.

The average score for senior executives is ---Select--- lower than higher than equal to the middle managers score. The standard deviation for senior executives is ---Select--- lower than higher than equal to the middle managers standard deviation.

6.

[-/4.54 Points]DETAILSASWSBE15 5.E.067.

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ASK YOUR TEACHER

According to the U.S. Census Bureau, the poverty rate in the United States in 2020 was 11.4%. Suppose that 340 people in the United States are randomly selected.

(a)

What is the expected number of people in the selected sample that are classified as living in poverty?

(b)

What is the variance for the number of people in the selected sample that are classified as living in poverty? (Round your answer to four decimal places.)

What is the standard deviation for the number of people in the selected sample that are classified as living in poverty? (Round your answer to four decimal places.)

7.

[-/4.54 Points]DETAILSASWSBE15 5.E.033.

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ASK YOUR TEACHER

You may need to use the appropriate appendix table or technology to answer this question.

Consider a binomial experiment with

n = 20

and

p = 0.70.

(Round your answers to four decimal places.)

(a)

Compute

f(13).

f(13) =

(b)

Compute

f(16).

f(16) =

(c)

Compute

P(x 16).

P(x 16) =

(d)

Compute

P(x 15).

P(x 15) =

(e)

Compute

E(x).

E(x) =

(f)

Compute

Var(x)

and .

Var(x)

==

8.

[-/4.54 Points]DETAILSASWSBE15 5.E.039.

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ASK YOUR TEACHER

According to a survey, 34.3% of households in the United States own a dog as a pet. Suppose that a company that sells dog food would like to establish a focus group to gather input on a new dog food marketing campaign. The company plans to contact 25 randomly selected households to invite people to join the focus group.

(a)

Compute the probability that 13 of these 25 households own a dog as a pet. (Round your answer to four decimal places.)

(b)

Compute the probability that 2 or fewer of these 25 households own a dog as a pet. (Round your answer to four decimal places.)

(c)

For the sample of 25 households, compute the expected number of households who own a dog as a pet.

(d)

For the sample of 25 households, compute the variance of the number of households who own a dog as a pet. (Round your answer to four decimal places.)

For the sample of 25 households, compute the standard deviation of the number of households who own a dog as a pet. (Round your answer to four decimal places.)

9.

[-/4.54 Points]DETAILSASWSBE15 5.E.070.MI.SA.

MY NOTES

ASK YOUR TEACHER

This question has several parts that must be completed sequentially. If you skip a part of the question, you will not receive any points for the skipped part, and you will not be able to come back to the skipped part.

Tutorial Exercise

A new automated production process averages 1.2 breakdowns per day. Because of the cost associated with a breakdown, management is concerned about the possibility of having three or more breakdowns during a day. Assume that breakdowns occur randomly, that the probability of a breakdown is the same for any two time intervals of equal length, and that breakdowns in one period are independent of breakdowns in other periods. What is the probability of having three or more breakdowns during a day?

10.

[-/4.54 Points]DETAILSASWSBE15 5.E.046.MI.SA.

MY NOTES

ASK YOUR TEACHER

This question has several parts that must be completed sequentially. If you skip a part of the question, you will not receive any points for the skipped part, and you will not be able to come back to the skipped part.

Tutorial Exercise

Phone calls arrive at the rate of 36 per hour at the reservation desk for Regional Airways.

(a)

Compute the probability of receiving six calls in a 5-minute interval of time.

(b)

Compute the probability of receiving exactly 10 calls in 20 minutes.

(c)

Suppose no calls are currently on hold. If the agent takes 5 minutes to complete the current call, how many callers do you expect to be waiting by that time? What is the probability that none will be waiting?

(d)

If no calls are currently being processed, what is the probability that the agent can take 6 minutes for personal time without being interrupted by a call?

11.

[-/4.6 Points]DETAILSASWSBE15 5.E.049.

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ASK YOUR TEACHER

You may need to use the appropriate appendix table or technology to answer this question.

Airline passengers arrive randomly and independently at the passenger-screening facility at a major international airport. The mean arrival rate is 10 passengers per minute, and passenger arrivals follow a Poisson distribution. (Round your answers to six decimal places.)

(a)

Compute the probability of no arrivals in a one-minute period.

(b)

Compute the probability that three or fewer passengers arrive in a one-minute period.

(c)

Compute the probability of no arrivals in a 9-second period.

(d)

Compute the probability of at least one arrival in a 9-second period.