Neve Commercial Bank is the only bank in the town of? York, Pennsylvania. On a typical? Friday, an average of 8 customers per hour arrive at the bank to transact business. There is one teller at the? bank, and the average time required to transact business is 4 minutes. It is assumed that service times may be described by the negative exponential distribution. A single line would be? used, and the customer at the front of the line would go to the first available bank teller. If a single teller is? used: a) the average time in the line b) the average number in the line c) the average time in the system d) the average number in the system e) the probability that the bank is empty f) if a second teller is added, find the new answers to parts (a) to (e)