# A PERT problem: calculating variance of critical path

Consider the tasks, durations, and predecessor relationships in the following network.

(see chart in attached file)

a. Draw the network:

b. Calculate Te for all tasks (fill in the table):

c. Calculate variance for all tasks (fill in the table):

d. Determine all paths, their estimated durations, and their variances:

e. Identify the critical path:

f. What is the likelihood (probability) of completing the project in 42 weeks?

#### Solution Summary

This posting contains a typical PERT problem with drawing the Network diagram, calculating Te, determining Critical path, and Variance of critival path and calculating Probability of completing the project in given time.