Scientists conducted an experiment to test the effects of five different diets on turkeys. They randomly assigned six turkeys to each of the five diet groups and fed them for a fixed period of time.

Group Weight Gained (pounds)

Control diet 4.1, 3.3, 3.1, 4.2, 3.6, 4.4

Control diet 1+level 1 of additive A 5.2, 4.8, 4.5, 6.8, 5.5, 6.2

Control diet 1+ level 2 of additive A 6.3, 6.5, 7.2, 7.4, 7.8, 6.7

Control diet 1 + level 1 of additive B 6.5, 6.8, 7.3, 7.5, 6.9, 7.0

Control diet 1 + level 2 of additive B 9.5, 9.6, 9.2, 9.1, 9.8, 9.1

a. Plot the data separately for each sample.

b. Compute y and s2 for each sample.

c. Is there any evidence of unequal variances or nonnormality? Explain.

d. Assuming that the five groups were comparable with respect to initial weights of the turkeys, use the weight-gained data to draw conclusions concerning the different diets. Use = .05.