5. A project manager has the following AON precedence network for a small project:

Time estimates are as follows:

Duration (Wksl Task Optimistic Most Likely Pessimistic 1 4 6 14 2 1 3 11 3 2 9 16 4 1 3 8

a. Find the expected duration of the project and its variance, according to the Classic PERT model.

b. Based on the Classic PERT model, what is the probability that the project will be completed within 13 weeks?

c. What is the true probability that the project will be completed within 13 weeks?