Management of a local bank is interested in assessing the process used in opening new checking accounts for bank customers. In particular, management would like to examine the time required to process a customer's request to open a new checking account. Currently, managers believe that it should take about 7 minutes to process such a request. Furthermore, they believe that the time required to process this type of request should be between LSL = 5.5 minutes and USL = 8.5 minutes. The file P20_12.xlsx contains the time required to process new checking account requests for each of 6 customers selected randomly on a given day. A different subsample of 6 customer requests was collected on each of 25 days.

a. Estimate Cp and the probability of meeting specifications. Is this a highly capable production process?

b. Estimate Cpk. Does your estimate of Cpk differ from that of Cp computed in part a? If so, how do you explain this difference?