Using PERT, a project team was able to determine that the expected project completion time for construction of a building is 21 months and the project variance is 4. Hint: By definition, the probability that the project team will complete the project in 21 months is 50%. a) What is the probability that the project will be completed in 20 months? b) What is the probability that the project will be completed in 23 months? c) What is the due date that would give the team a 95% chance of completion?