9 An engineering firm retains a technical specialist to assist four design engineers working on a project. The help that the specialist gives engineers ranges widely in time consumption. The specialist has some answers available in memory; others require computation, and still others require significant search time. On the average, each request for assistance takes the specialist one hour. The engineers require help from the specialist on the average of once each day. Because each assistance takes about an hour, each engineer can work for seven hours, on the average, without assistance. One further point: Engineers needing help do not interupt if the specialist is already involved with another problem. Treat this as a finite queuing problem and answer the following questions: a How many engineers, on average, are waiting for the technical specialist for help?

b. What is the average time that an engineer has to wait for the specialist?

c. What is the probability that an engineer will have to wait in line for the specialist?