Question: Customers arrive at a grocery stores checkout counter according to a Poisson process with rate I per minute. Each customer carries a number of items that is uniformly distibuted between 1 and 40. The store has two checkout counters, each capable of processing items at a rate of 15 per minute. To reduce the customer waiting time in queue, the store manager considers dedicating one of the two counters to customers with x items or less and dedicating the other counter to customers with more than x items. Write a small computer program to find the value of x that minimizes the average customer waiting time.