The management of a grocery store observes various employees for work productivity. Table 10.3.3 gives the number of customers served by each of its four checkout lanes per hour.
|
Table
|
|
Lane 1
|
Lane 2
|
Lane 3
|
Lane 4
|
|
16
|
11
|
8
|
21
|
|
18
|
14
|
12
|
16
|
|
22
|
10
|
17
|
17
|
|
21
|
10
|
10
|
23
|
|
15
|
14
|
13
|
17
|
|
10
|
15
|
(a) Construct an analysis-of-variance table and interpret the results. Indicate any assumptions that were necessary.
(b) Test whether there is a difference between the mean number of customers served by the four employees at the 0.05 level. Assume that the conditions of completely randomized design are met.