A contractor's project being analyzed by PERT has an estimated time for the critical path of 120 days.The sum of all activity variances is 81;the sum of variances along the critical path is 64.What is the probability that the project will take 130 or more days to complete?
A)0.1057
B)0.1335
C)0.8512
D)0.8943
E)1.29

Question

Quizplus · Accepted Answer

From the given data:
- The standard deviation of the critical path is √64 = 8
- The standard deviation of the entire project is (81)^(1/2) = 9
To calculate the probability of completing the project in 130 days or more, we need to standardize the value using z-score.
z = (130-120)/9 = 1.11
Using a standard normal table or calculator, we can find the probability of z being greater than 1.11, which is 0.1335.
Therefore, the probability of completing the project in 130 days or more is 0.1335, which is closest to option A (0.1057 is too small and 0.8512 and 0.8943 are too large).

A Contractor's Project Being Analyzed by PERT Has an Estimated