The process of being served at a bank consists of two independent parts—the time waiting in
line and the time it takes to be served by the teller. Suppose that the time waiting in line has
an expected value of 4 minutes, with a standard deviation of 1.2 minutes, and the time it takes
to be served by the teller has an expected value of 5. 5 minutes, with a standard deviation of
1.5 minutes. Compute the
a. expected value of the total time it takes to be served at the bank.