The manager of the accounting office of a large hospital has the business objective of reducing the number of incorrect account numbers entered into the computer system. A subgroup of 200 account numbers is selected from each day's output, and each account number is inspected to determine whether it is a nonconforming item. The results for a period of 39 days are stored in Errorspc.
a. Construct a p chart for the proportion of nonconforming items. Does the process give an out-of-control signal?
b. Based on your answer in (a), if you were the manager of the accounting office, what would you do to improve the process of account number entry?