A group of 10 students share 2 computers. For each student
the following is true: events that require a computer occur
at the rate of 0.5/hour, the average time per computer use
is 20 minutes. Both service and arrival processes are Poisson.
When a student tries to use a computer and finds them both
busy, the student wastes his or her time watching television.
Some results of the queuing analysis are shown below.
Quantity

Value

Units 
Mean Number in System

1.912

students 
Mean Number in Queue

1.486

students 
Mean Number in Service

1.791

students 
Throughput Rate

3.582

students/hour 
Efficiency

0.674


a. Write the Kendall notation describing the system.
b.What proportion of the total computer time are the computers
idle?
c. What proportion of the time are students wasting time watching
the TV?
d. If another student is allowed to share the system (making
11 in all), how will the Efficiency change? (up, down, or stay
the same)
