Chapter 8.3, Problem 17E

For Exercises 7 through 23, perform each of the following steps.

a. State the hypotheses and identify the claim.

b. Find the critical value(s).

c. Find the test value.

d. Make the decision.

e. Summarize the results.

Use the traditional method of hypothesis testing unless otherwise specified.

17. Medical Operations The director of a medical hospital feels that her surgeons perform fewer operations per year than the national average of 211. She selected a random sample of 15 surgeons and found that the mean number of operations they performed was 208.8. The standard deviation of the sample was 3.8. Is there enough evidence to support the director’s feelings at α = 0.10? Would the null hypothesis be rejected at α = 0.01?