Researchers conducted an experiment to compare the effectiveness of four new weight-reducing agents to that of an existing agent. The researchers randomly divided a random sample of 50 males into five equal groups with preparation A1 assigned to the first group, preparation A2 to the second group, and so on. The fifth group was given the standard preparation, labeled S. They gave a prestudy physical to each person in the experiment and told him how many pounds overweight he was. A comparison of the mean numbers of pounds overweight for the groups showed no significant differences. The researchers then began the study program, and each group took the prescribed preparation for a fixed period of time. The weight losses recorded at the end of the study were recorded, and can be found in the attached data set. Answer the following questions using SAS, and append your code.

a. Test for differences among the five weight-reducing agents using ANOVA with alpha= 0.01.

b. Check the ANOVA assumptions. Are your conclusions from part a. warranted?

loss regime

12.4 A1

10.7 A1

11.9 A1

11 A1

12.4 A1

12.3 A1

13 A1

12.5 A1

11.2 A1

13.1 A1

9.1 A2

11.5 A2

11.3 A2

9.7 A2

13.2 A2

10.7 A2

10.6 A2

11.3 A2

11.1 A2

11.7 A2

8.5 A3

11.6 A3

10.2 A3

10.9 A3

9 A3

9.6 A3

9.9 A3

11.3 A3

10.5 A3

11.2 A3

12.7 A4

13.2 A4

11.8 A4

11.9 A4

12.2 A4

11.2 A4

13.7 A4

11.8 A4

12.2 A4

11.7 A4

8.7 S

9.3 S

8.2 S

8.3 S

9 S

9.4 S

9.2 S

12.2 S

8.5 S

9.9 S