The Baytown Post Office has four stations for service. Customers line up in single file for service on an FIFO basis. The mean arrival rate is 40 per hour, Poisson distributed, and the mean service time per server is five minutes, exponentially distributed. Compute the operating characteristics for this operation. Does the operation appear to be satisfactory in terms of: (a) postal workers’ (servers’) idle time; (b) customer waiting time and/or the number waiting for service; and (c) the percentage of the time a customer can walk in and get served without waiting at all?