Chapter 12.1, Problem 20E

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.

20. Average Debt of College Graduates Kiplinger’s listed the top 100 public colleges based on many factors. From that list, here is the average debt at graduation for various schools in four selected states. At a = 0.05, can it be concluded that the average debt at graduation differs for these four states?

Source: www.Kiplinger.com