Problem 15-5 the reference desk of a university library receives requests for assistance. assume that a poisson probability distribution with an arrival rate of 10 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 12 requests per hour. what is the probability that no requests for assistance are in the system? if required, round your answer to four decimal places. p0 = what is the average number of requests that will be waiting for service? if required, round your answer to four decimal places. lq = what is the average waiting time in minutes before service begins? if required, round your answer to four decimal places. wq = hours 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 = hours what is the probability that a new arrival has to wait for service? if required, round your answer to four decimal places. pw =