Wallington Copy Center provides self-service machines so that students can make last-minute copies of class presentations (either that, or printing 90 copies in the computer lab!). For this self-service operation, arrival patterns follow a Poisson distribution, with a mean rate of 15 arrivals per hour. With the current copying equipment, the average service time is three minutes. A new generation of machines is available that will reduce this to an average of two minutes. (a) Wallington currently leases one old-technology machine for student self-service. What is the average number of students in system in the current system. If a new generation machine can be leased to replace the old machine, what will be the new average number of students in system? (2 points) (b) Rather than lease the new machine, Wallington could lease a second, old-technology machine. What will be the average number of students in system in this case? (2 points) (c) The average value of time for the students requiring copying is $15 per hour (hey, they're trying to rush to class!). From the perspective of overall cost of leasing, the option of leasing two old machines is $3 per hour more expensive than the option of leasing one new machine. However, the Copy Center is mindful of customer's waiting cost and wants to choose the option with less total cost.(customer cost + service cost). Which is better, to lease a new machine or to lease another old- technology machine? (3 points)