154 PCB in plant discharge (cont’d). Refer to Exercise 153.

a. In the context of the problem, define a Type II error.

b. Calculate b for the test described in part a of Exercise 153, assuming that the true mean is m = 3.1 ppm.

c. What is the power of the test to detect the effluent’s departure from the standard of 3.0 ppm when the mean is 3.1 ppm?

d. Repeat parts b and c , assuming that the true mean is 3.2 ppm. What happens to the power of the test as the plant’s mean PCB departs farther from the standard?