4. A bank is considering opening a drive-through window for customer service. Customers are estimated to arrive at the average rate of 15 per hour. The teller who works at the window can service customers at the average rate of one every three minutes. Assume Poisson arrivals and exponential service times. a. Find the average number of customers in the waiting line (waiting but not being serviced). b. Find the average waiting time in the system (including waiting in line and in service). 0. Suppose that now the service times are deterministic at the same rate; that is, the teller can service exactly one customer every three minutes. Do you think your answer in (b) will become larger, or smaller, or remain the same? No calculation needed