allowed. Each representative can accommodate an average of 11 calls per hour. The arrival rate is 22 calls per hour. a. How many extension lines should be used if the company wants to handle 90% of the calls immediately? b. What is the probability that a call will receive a busy signal if your recommendation in part (a) is used? If required, round your answer to four decimal places. c. What number of calls, in decimal form, receive a busy signal for the current telephone system with two extension lines? If required, round your answer to four decimal places