Problem 15-5 (Algorithmic) The reference desk of a university library receives requests for assistance. Assume that a Poisson probability distribution with an arrival rate of 7 requests per hour can be used to describe the arrival pattern and that service times follow an exponential probability distribution with a service rate of 8 requests per hour. a. What is the probability that no requests for assistance are in the system? If required, round your answer to four decimal places. Po = .1667 X b. What is the average number of requests that will be waiting for service? If required, round your answer to four decimal places. La = 4.1667 c. What is the average waiting time in minutes before service begins? If required, round your answer to four decimal places. Wa = .4167 X hours d. What is the average time at the reference desk in minutes (waiting time plus service time)? If required, round your answer to one decimal place. W= .5 X hours e. What is the probability that new arrival has to wait for service? If required, round your answer to four decimal places. Pw = .8333 X