Fowle Marketing Research, Inc., bases charges to a client on the assumption that telephone surveys can be completed within 15 minutes or less. If more time is required, a premium rate is charged. With a sample of 35 surveys, a population standard deviation of 4 minutes, and a level of significance of .01, the sample mean will be used to test the null hypothesis H0: μ 15.

a. What is your interpretation of the Type II error for this problem? What is its impact on the firm?

b. What is the probability of making a Type II error when the actual mean time is

μ  17 minutes?

c. What is the probability of making a Type II error when the actual mean time is

μ  18 minutes?

d. Sketch the general shape of the power curve for this test.