A student computer laboratory has a single laser printer. Jobs queue up on the printer from the network server in the lab and are completed on a first-come, first-served basis. The average printing job requires four minutes, but the times vary considerably. Experience has shown that the distribution of times closely follows an exponential distribution. At peak times, about 12 students per hour require use of the printer, but the arrival of jobs to the printer can be assumed to occur completely at random. Assuming a peak traffic period, determine the following: a. The average number of jobs in the printer queue. b. The average flow time of a job