Pentagon speeds up order-to-delivery times. Following the initial Persian Gulf War, the Pentagon changed its logistics processes to be more corporate-like. The extravagant

“just-in-case” mentality was replaced with “just-intime”

systems. Emulating Federal Express and United Parcel Service, the Pentagon now expedites deliveries from factories to foxholes with the use of bar codes, laser cards, radio tags, and databases to track supplies. The following table contains order-to-delivery times (in days)

for a sample of shipments from the United States to the LO3 Persian Gulf and a sample of shipments from the United States to Bosnia.

Persian Gulf Bosnia 28.0 15.1 20.0 6.4 26.5 5.0 10.6 11.4 9.1 6.5 35.2 6.5 29.1 3.0 41.2 7.0 27.5 5.5

a. Determine whether the variances in order-to-delivery times for Persian Gulf and Bosnia shipments are equal.

Use a = .05.

b. Given your answer to part

a, is it appropriate to construct a confidence interval for the difference between the mean order-to-delivery times? Explain.