Oneway ANOVA with pair wise comparison (Turkey's test).
An experiment was conducted to compare the effectiveness of 5 different weight reducing agents. A random sample of 50 males was at random divided into five equal groups, with preparation A assigned to the first group, B to the second, and so on. Each person in the experiment was given a prestudy physical and told how many pounds overweight he was. A comparison of the mean number of pounds overweight for groups showed no significant differences. The study was then begun, with each group taking the prescribed preparation for a fixed period of time. At the end of the study period, weight losses were recorded. The data are given here.
A

12.4

10.7

11.9

11.0

12.4

12.3

13.0

12.5

11.2

13.1

B

9.1

11.5

11.3

9.7

13.2

10.7

10.6

11.3

11.1

11.7

C

8.5

11.6

10.2

10.9

9.0

9.6

9.9

11.3

10.5

11.2

D

8.7

9.3

8.2

8.3

9.0

9.4

9.2

12.2

8.5

9.9

E

12.7

13.2

11.8

11.9

12.2

11.2

13.7

11.8

11.5

11.7

Assume preparation D was a placebo. Use Scheffe's procedure to compare an average response of A, B, C, and E to the response for D.