For Exercises 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 from 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.

Annual child care costs for infants are considerably higher than for older children. At α = 0.05, can you conclude a difference in mean infant day care costs for different regions of the United States? (Annual costs per infant are given in dollars.)

New England 10,390 7,592 8,755 9,464 7,328 Midwest 9,449 6,985 6,677 5,400 8,372 Southwest 7,644 9,691 5,996 5,386