Let the time (in weeks) from shipment of a defective product until the customer returns the product. Suppose that the minimum return time is and that the excess g 5 3.5 1021 X 5 a 5 2.5 b 5 200 P(1.5 # X # 6)

P(X # 6)

a 5 2 b 5 3 over the minimum has a Weibull distribution with parameters and (see “Practical Applications of the Weibull Distribution,” Industrial Quality Control, Aug. 1964: 71–78).

a. What is the cdf of X?

b. What are the expected return time and variance of return time? [Hint: First obtain and .]

c. Compute .

d. Compute .