Seventy-five percent of calls arriving at a help line can be handled by the person who answers the phone, but the remaining 25% of them will need to be referred to someone else. Assume that every call requires one minute of attention by the person who answers the phone (either to answer the question or to figure out how the referral should be handled). Calls that are referred need an additional amount of time, as given in the table below.
Time Required Probability
3 minutes 0.25
5 minutes 0.35
10 minutes 0.40
Callers are served on a first come, first served basis, and are put on hold until the line is free.
a. Use the random numbers to simulate what happens to 10 callers.
.82 .39 .16 .79 .56 .62 .13 .04 .42 .81
.85 .32 .64 .90 .73 .02 .76 .03 .86 .67
b. What percentage of your callers needs to be referred? Of those who had to be referred, what is the average referral time?
c. Develop an Excel program and simulate this problem for 25 calls. Compare your results with the ones in part a and report the differences.
Excel file contains solution of simulation problem.