Chapter 8.2, Problem 13E

Testing the Difference Between Two Means in Exercises 13–22, (a) identify the claim and state H₀ and H_a, (b) find the critical value(s) and identify the rejection region(s), (c) find the standardized test statistic t, (d) decide whether to reject or fail to reject the null hypothesis, and (e) interpret the decision in the context of the original claim. Assume the samples are random and independent, and the populations are normally distributed.

13. Veterinarian Visits A pet association claims that the mean annual costs of routine veterinarian visits for dogs and cats are the same. The results for samples of the two types of pets are shown at the left. At α = 0.10, can you reject the pet association's claim? Assume the population variances are equal. (Adapted from American Pet Products Association)

Sample Statistics for Annual Costs of Routine Veterinarian Visits

Dogs	Ca1s
${\bar{x}}_1\text{ = \$263}$	${\bar{x}}_2\text{ = \$183}$
S1 = $30 s,	S2 = $27
n1 = 16	n2 = l8

TABLE FOR EXERCISE 13