One way Analysis Of Variance in Excel.
There are four auto body shops in a community and all claim to promptly serve customers. To check if there is any difference in service, customers are at random selected from each repair shop and their waiting times in days are recorded. The output from the statistical software package is:
|
Summary
|
|
Groups
|
Count
|
Sum
|
Average
|
Variance
|
|
Body Shop A
|
3
|
15.4
|
5.133333
|
0.323333
|
|
Body Shop B
|
4
|
32
|
8
|
1.433333
|
|
Body Shop C
|
5
|
25.2
|
5.04
|
0.748
|
|
Body Shop D
|
4
|
25.9
|
6.475
|
0.595833
|
|
ANOVA
|
|
Source of Variation
|
SS
|
df
|
MS
|
F
|
p-value
|
|
Between Groups
|
23.37321
|
3
|
7.791069
|
9.612506
|
0.001632
|
|
Within Groups
|
9.726167
|
12
|
0.810514
|
|
|
|
Total
|
33.09938
|
15
|
|
|
|
Is there evidence to suggest a difference in mean waiting times at the four body shops? Utilize the .05 significance level.