Ashford BUS308 Week 2 Chapter 10 Assignment

Question 1 Exercise 10.07 (Inferences About the Difference Between Two Population Means: Sigmas Known)

Consumer Reports uses a survey of readers to obtain customer satisfaction ratings for the nation's largest supermarkets (Consumer Reports website). Each survey respondent is asked to rate a specified supermarket based on a variety of factors such as quality of products, selection, value, checkout efficiency, service, and store layout. An overall satisfaction score summarizes the rating for each respondent with meaning the respondent is completely satisfied in terms of all factors. Sample data representative of independent samples of Publix and Trader Joe's customers are shown below.

Excel File: data10-07.xlsx

Publix	Trader Joe's

a. Formulate the null and alternative hypotheses to test whether there is a difference between the population mean customer satisfaction scores for the two retailers.

b. Assume that experience with the Consumer Reports satisfaction rating scale indicates that a population standard deviation of is a reasonable assumption for both retailers. Conduct the hypothesis test and report the -value.

p-value = (to decimals)

At a level of significance what is your conclusion?

1. Reject . There is not sufficient evidence to conclude that the mean satisfaction scores differ for the two retailers.
2. Do not reject . There is not sufficient evidence to conclude that the mean satisfaction scores differ for the two retailers.
3. Reject . There is sufficient evidence to conclude that the mean satisfaction scores differ for the two retailers.
4. Do not reject . There is sufficient evidence to conclude that the mean satisfaction scores differ for the two retailers.

c. Which retailer, if either, appears to have the greater customer satisfaction?

Provide a confidence interval for the difference between the population mean customer satisfaction scores for the two retailers. Enter negative values as negative numbers, if any.

to (to decimals)

 

Question 2 Exercise 10.17 (Inferences About the Difference Between Two Population Means: Sigmas Unknown)

Periodically, Merrill Lynch customers are asked to evaluate Merrill Lynch financial consultants and services. Higher ratings on the client satisfaction survey indicate better service with the maximum service rating. Independent samples of service ratings for two financial consultants are summarized here. Consultant A has years of experience, whereas consultant B has year of experience. Use and test to see whether the consultant with more experience has the higher population mean service rating. Round degrees of freedom to previous whole number.

Excel File: data10-17.xlsx

Consultant A		Consultant B

a. State the null and alternative hypotheses.
:

:

b. Compute the value of the test statistic. (to 2 decimals)

c. What is the p-value? Use Table 2 from Appendix B to find the values that bound the test statistic.

d. What is your conclusion?

Question 3  Exercise 10.27 (Inferences About the Difference Between Two Population Means: Matched Samples)

A personal fitness produces both a deluxe and a standard model of a smoothie blender for home use. Selling prices obtained from a sample of retail outlets follow.

Excel File: data10-27.xlsx

	Model Price ($)				Model Price ($)
Retail Outlet	Deluxe	Standard		Retail Outlet	Deluxe	Standard
1	39	27		5	40	30
2	39	28		6	39	34
3	45	35		7	35	29
4	38	30

Round your answers to 2 decimal places.

a. The manufacturer's suggested retail prices for the two models show a price differential. Use a level of significance and test that the mean difference between the prices of the two models is .

b. What is the confidence interval for the difference between the mean prices of the two models?

to

Question 4 Exercise 10.29 Algo (Inferences About the Difference Between Two Population Proportions)

Consider the hypothesis test below.

The following results are for independent samples taken from the two populations.

Sample 1	Sample 2

Use pooled estimator of .

a. What is the -value (to 4 decimals)? Use Table 1 from Appendix B.

b. With , what is your hypothesis testing conclusion?

Question 5 Exercise 10.41 (Inferences About the Difference Between Two Population Means: Sigmas Unknown)

The National Association of Home Builders provided data on the cost of the most popular home remodeling projects. Sample data on cost in thousands of dollars for two types of remodeling projects are as follows.

Excel File: data10-41.xlsx

Kitchen	Master Bedroom		Kitchen	Master Bedroom
25.2	18.0		23.0	17.8
17.4	22.9		19.7	24.6
22.8	26.4		16.9	21.0
21.9	24.8		21.8
19.7	26.9		23.6

a. Develop a point estimate of the difference between the population mean remodeling costs for the two types of projects. Enter negative values as negative numbers.
Point estimate
(Report in dollars with no commas in your answer.)

b. Develop a confidence interval for the difference between the two population means. (to 1 decimal and enter negative values as negative numbers)
( , ) in thousands of dollars.

Question 6 Exercise 10.43 (Inferences About the Difference Between Two Population Proportions)

Country Financial, a financial services company, uses surveys of adults age and older to determine whether personal financial fitness is changing over time. A recent sample of adults showed indicating that their financial security was more than fair. Just a year prior, a sample of adults showed indicating that their financial security was more than fair.

a. State the hypotheses that can be used to test for a significant difference between the population proportions for the two years.

b. Conduct the hypothesis test and compute the -value. Round your answer to four decimal places.
p-value =

At level of significance, what is your conclusion?

1. Reject . There is not sufficient evidence to conclude that the population proportions are not equal. The data do not suggest that there has been a change in the population proportion saying that their financial security is more than fair.
2. Reject . There is sufficient evidence to conclude that the population proportions are not equal. The data suggest that there has been a change in the population proportion saying that their financial security is more than fair.
3. Do not reject . There is not sufficient evidence to conclude that the population proportions are not equal. The data do not suggest that there has been a change in the population proportion saying that their financial security is more than fair.
4. Do not reject . There is sufficient evidence to conclude that the population proportions are not equal. The data suggest that there has been a change in the population proportion saying that their financial security is more than fair.

c. What is the confidence interval estimate of the difference between the two population proportions? Round your answers to four decimal places.
Confidence Interval ( to )