During the morning hours at a catalog sales department, telephone calls come in at the rate (

Poisson)

of 40 per hour. Calls that cannot be answered immediately are put on hold. The system can handle eight callers on hold. If additional calls come in, they receive a busy signal. The three customer service representatives who answer the calls spend an average of three minutes with a customer.

a. What is the probability that a caller will get a busy signal? (Hint: Solve for log K or ln K using trial and error.)

b. What is the probability that a customer will be put on hold?

 LO.1