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 sales people are recorded here:

Electronic Stores: 5,4,3,3,3 = 3.6
Department Stores: 9,7,8,6,5 = 7.2
Computer Stores: 7,4,8,4,3 = 5.2

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

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