A computer manufacturer is introducing a new product specifically targeted at the home market and wishes to compare the effectiveness of three sales strategies: computer stores, home electronics stores, and department stores. Numbers of sales by 15 salespeople are recorded below:

Electronics store: 5, 4, 3, 3, 3

Department store: 9, 7, 8, 6, 5

Computer store: 7, 4, 7, 4, 3

a. Test the hypothesis that there is no difference between the means of the retailers (x = .05).

b. Select a multiple comparison test, if necessary, to determine which groups differ in mean sales (x = .05)