Zimmermans Bank is the only bank in the small townof St. Thomas. 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 exponentialdistribution. 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, find:

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.