cor 1.3

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 specied retailer in terms of six factors: quality of products, selection, value, checkout efciency, service, and store layout. An overall satisfaction score summarizes the rating for each respondent with 100 meaning the respondent is completely satised 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 n=25 n=30 X1=79 X2=72 (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. (Let '11 = population mean satisfaction score for Retailer A customers and p2 = population mean satisfaction score for Retailer B customers.) Ho: \"1 ' #2 = Ha: p1 '12 z 0 O HO: p1 #2 2 0 H3: \"1 \"2 0 J (b) Assume that experience with the satisfaction rating scale of the magazine indicates that a population standard deviation of 13 is a reasonable assumption for both retailers. Conduct the hypothesis test. =ind the value of the test statistic. (Round your answer to two decimal places.) 1.99 'y Find the p-value. (Round your answer to four decimal places.) pvalue = 0.0468 At a 0.05 level of significance what is your conclusion? O Reject H0. There is insufficient evidence to conclude that the population mean satisfaction scores differ for the two retailers. 0 Do not reject H0. There is insufcient evidence to conclude that the population mean satisfaction scores differ for the two retailers. Reject H0. There is sufficient evidence to conclude that the population mean satisfaction scores differ for the two retailers. 0 Do not Reject H0. There is sufficient evidence to conclude that the population mean satisfaction scores differ for the two retailers. 9/ Provide a 95% condence interval for the difference between the population mean customer satisfaction scores for the two retailers. (Round your answers to two decimal places.) 0.00 x to 14.00 x Which retailer, if either, appears to have the greater customer satisfaction? The 95% condence interval X zero. This suggests that the Retailer A has a I population mean customer satisfaction score than Retailer B