Question

A magazine uses a survey of readers to obtain customer satisfaction ratings for the nation's largest retailers. Each survey respondent is asked to rate a specified retailer in terms of six factors: quality of products, selection, value, checkout efficiency, service, and store layout. An overall satisfaction score summarizes the rating for each respondent with 100 meaning the respondent is completely satisfied in terms of all six factors. Sample data representative of independent samples of Retailer A and Retailer B customers are shown below.

Retailer A	Retailer B
n1 = 25	n2 = 30
x1 = 79	x2 = 71

Assume that experience with the satisfaction rating scale of the magazine indicates that a population standard deviation of 11 is a reasonable assumption for both retailers. Conduct the hypothesis test.

Find the value of the test statistic. (Round your answer to two decimal places.)

Find the p-value. (Round your answer to four decimal places.)

p-value =

Provide a 95% confidence interval for the difference between the population mean customer satisfaction scores for the two retailers. (Round your answers to two decimal places.)

to

Answer 1

Here using ti-83 calculator.

Test statistic :

Z=2.69

P-value :

P=0.0072

95% confidence level at alpha=5%=0.05

Conclusion :- Reject H0.

95% confidence interval for the difference between the population mean customer satisfaction scores for the two retailers is 2.16 and 13.84.