HP 12c Solutions Handbook page 146

What is the average number of customers in the waiting line at any time?
The average waiting time? What is the average total time for a customer
to wait and be checked out? The average number of customers in the
system?
Keystrokes
.5 1
.9 2
2
1
1
2
1
With an HP-12C program on can readily calculate the necessary
probabilities for this type of problem (dispensing with the use of tables)
and perform additional calculations as well.
KEYSTROKES
CLEAR
1
0
0
Display
0.50
0.56
0.69
1.39
2.50
1.25
0
0
09
16
Average # customers waiting in
queue.
Average waiting time.
Average total time in the system.
Average # customers in system.
DISPLAY
00-
01-
02-44 33
03-45 48
04- 45
05-
06- 43 34
07-43, 33 09
08-43, 33 16
09- 40
10- 21
11- 43 36
12- 43
13- 10
145
1
0
0
0
0
3