The Acme Grocery Store is a medium-sized store with 6 checkout counters. The store is open from 7am to 9pm, 7 days a week. The store manager is concerned about long lines at the checkout registers during the peak hours of 3:30-6:30pm Mon-Fri. Currently two checkout clerks work two registers during this time period. The manager wants to determine the optimal number of registers and employees needed to minimize customer wait times to less than 3 minutes. Data was collected on the arrival rates of customers to the checkout registers from 3:30pm to 6:00pm during the week. Overall arrival rate is said to be poisson distributed. Service time is exponentially distributed with each checkout clerk servicing a mean of 17 customers every hour