Chapter 12.1, Problem 12E

For Exercises 7 through 20, assume that all variables are normally distributed, that the samples are independent, that the population variances are equal, and that the samples are simple random samples, one front each of the populations. Also, for each exercise, perform the following steps.

a. State the hypotheses and identify the claim.

b. Find the critical value.

c. Compute the test value.

d. Make the decision.

e. Summarize the results, and explain where the differences in the means are.

Use the traditional method of hypothesis testing unless otherwise specified.

12. Weight Gain of Athletes A researcher wishes to see whether there is any difference in the weight gains of athletes following one of three special diets. Athletes are randomly assigned to three groups and placed on the diet for 6 weeks. The weight gains (in pounds) are shown here. At a = 0.05, can the researcher conclude that there is a difference in the diets?

Did A	Diet B	Diet C
3	10	8
6	12	3
7	11	2
4	14	5
	8
	6

A computer printout for this problem is shown. Use the P-value method and the information in this printout to test the claim. (The information in this exercise will be used in Exercise 4 of Section 12-2.)