Question: A computer center has two color printers. Students arrive at a rate of one every 8 ± 2 minutes to use the color printer. They can be interrupted by professors, who arrive at a rate of one every 12 ± 2 minutes. There is one systems analyst who can interrupt anyone, but students are interrupted before professors. The systems analyst spends 6 ± 4 minutes on the color printer and then returns in 20 ± 5 minutes. Professors and students spend 4 ± 2 minutes on the. color printer. If a person is interrupted, that person joins the head of the queue and resumes service as soon as possible. Simnlate for 50 professor-or-analyst jobs. Estimate the interruption rate per hour, and the mean length of the waiting line of students.