Given an activity's optimistic,most likely,and pessimistic time estimates of 2,10,and 20 days respectively,compute the PERT variance for this activity.
A)3
B)6
C)9
D)18
E)None of the above

Question

Quizplus · Accepted Answer

PERT variance is calculated as (optimistic time + 4 x most likely time + pessimistic time)/6 - optimistic time. 
Substituting the given values, we get (2 + (4 x 10) + 20)/6 - 2 = 9. Therefore, the PERT variance for this activity is 9. The closest option is C) 9.

Given an Activity's Optimistic,most Likely,and Pessimistic Time Estimates of 2,10,and