Della works as a project manager for BlueWell Inc. She has asked her assistant Beth to provide
activity duration estimate for an activity. Beth provides Della the following estimate chart:

What will be the activity duration according to the PERT three-point analysis?

A.
19

B.
24

C.
29

D.
46

Explanation:
A three-point estimate records the optimistic, most likely, and the pessimistic duration and then
records an average for the predicted duration. Three-point estimate is a way to enhance the
accuracy of activity duration estimates. This concept is originated with the Program Evaluation and
Review Technique (PERT). PERT charts the following three estimates: Most likely (TM): The
duration of activity based on realistic factors such as resources assigned, interruptions, etc.
Optimistic (TO): The activity duration based on the best-case scenario Pessimistic (TP): The
activity duration based on the worst-case scenario The expected (TE) activity duration is a
weighted average of these three estimates: TE = (TO + 4TM + TP) / 6
Duration estimates based on the above equations (sometimes simple average of the three
estimates is also used) provide more accuracy.
Here it is,
TE = ( 24 + 28*4 + 36) / 6
= 272/6
= 29 (approx)
Answer options B, D, and A are incorrect. These are not the valid answers for this question.