Ashford MGMT1501 Statistics for Manager I Assignment 4

MGMT 1501 – Statistics for Manager I

Assignment 4

Question 1 Consumer Reports uses a survey of readers to obtain customer satisfaction ratings for the nations’ largest retailers.  Each survey respondent is asked to rate a specified retailer in term 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 Target and Walmart customers are shown below.

Target   Walmart

n_1=25 n_2=30

x ?_1=79                x ?_2=71

Assume that experience with the consumer Reports satisfaction rating scale indicates that a population standard deviation of 12 is a reasonable assumption for both retailers.  Conduct the hypothesis test to test whether there is a difference between the population mean customer satisfaction scores for the two retailers.  At a 0.05 level of significance what is your conclusion?

Question 2 A random sample of 10 students was selected at Excelsior University for a study of how students change the way they spend their out-of-class time from junior to senior year.  As part of the study, when the students in the sample were in their junior year they were asked to estimate how much time they spent on social media like Facebook, Twitter, etc., on a typical class night.  An identical question was asked of the same 10 students in their senior year.  The table below shows the responses.  Assuming that the necessary population conditions are satisfied, is there evidence to suggest that the average time spent on social media by students at university is unchanged from junior to senior year? Conduct an appropriate test. Draw a conclusion at 0.05 level of significance.

Student                1              2              3              4              5              6              7              8              9              10

Junior    180         0              60           100         130         60           20           200         90           120

Senior   120         20           50           80           130         80           20           170         50           100

Question 3 Two groups of 15 consumers each were asked to read through a magazine that contains your company’s ad in one of two versions.  One sample group was given the magazine containing version A of the ad; the other, version B.  Each group was then asked to list as many ad and product details as they could recall.  For the version A group, the average number of details was 10.2, with a standard deviation of 5.4.  For the version B group, the average was 7.2, with standard deviation of 3.9.

                [10 pts]Using a significance level of 0.05, construct the appropriate hypothesis test to test a null hypothesis that there is no difference in the average recall rate for the two ad versions.  Use P-value approach to make the decision. Assume the degree of freedom is equal to 25.

                [5 pts]Find a 95% confidence interval estimate for the difference between the average recall rate for the two ad versions.

Question 4 According to the study conducted for Gateway Computers, 59% of men of 70% of women say that weight is an extremely/very important factor in purchasing a laptop computer.  Suppose this survey was conducted using 374 men and 481 women. 

                [10 pts]Do these data show enough evidence to declare that a significantly higher proportion of women than more men believe that weight is an extremely/very important factor in purchasing a laptop computer?  Use a 5% level of significance.

                [5 pts]Develop a 95% confidence interval for the difference in the true proportion of women and men believe that weight is an extremely/very important factor in purchasing a laptop computer.  Explain your results.