Assignment 7a

Willow Brook National bank operates a drive-up teller window that allows customers to complete bank transactions without getting out of their cars. On weekday mornings, arrivals to the drive-up teller window occur at random with a Poisson distribution with arrival rate of 20 customers per hour. (All applicable formulas are required)

1). how much is the mean number of arrivals per minute? the arrival rate .

Assume that the service times for the drive-up teller follow an exponential probability distribution with a service rate of 40 customers per hour.

2) how much is the mean number of customers that can be served per minute? the service rate .

3) The probability that no customers are in the system

4) The average number of customers waiting

5) The average number of customers in the system

6)the average time a customer spends waiting

7) The average time a customer spends in the system

8) The probability that arriving customers will have to wait for service.

9) The probability that 3 customers in the system.