Chapter 19, Problem 35PS

Refer to Problem 19.22 concerning waiting time for customers at a bank (data stored in BankTime). Suppose management has a USL of five minutes on waiting time and specified that at least $99\%$ of the waiting times must be less than five minutes in order for the process to be considered capable.

a. Estimate the percentage of the waiting times that are inside the speci�cation limits. Is the process capable of meeting the company policy?

b. If management implemented a new policy, starting that $99.7\%$ of all waiting times are required to be within specifications, is this process capable of reaching that goal? Explain.