If the mean critical path time for a CPM/PERT project network is 30 weeks and the variance is 7.20 weeks,the probability that the project will be completed in 27 weeks is approximately
A).3409
B).1313
C).1591
D).2736

Question

Quizplus · Accepted Answer

To find the probability that the project will be completed in 27 weeks, we need to standardize the value using the formula:
z = (x - mean) / standard deviation

Here, x = 27 weeks, mean = 30 weeks, and standard deviation = sqrt(variance) = sqrt(7.20) = 2.68 weeks.

Substituting the values, we get:
z = (27 - 30) / 2.68 = -1.12

Using a standard normal table, the probability corresponding to z = -1.12 is approximately 0.1313 or 13.13%. Therefore, the best choice is B.

If the Mean Critical Path Time for a CPM/PERT Project