Refer to problem 18.20 on page 726 concerning waiting time for customers at a bank. Suppose management has set an upper specification limit of 5 minutes on waiting time and that at least 99% of the waiting times must be less than 5 minutes in order for the process to be considered capable.

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

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