9. A project has the following activities, precedence relationships, and time estimates: Prede- Most Activity cessor Optimistic Pessimistic Likely A none 8 10 10 B A 20 25 22 C A 14 21 17 DB 5 9 8 E C 3 42 15 F D, E 21 87 45

a. Compute the mean and variance for each of the activities.

b. Draw a precedence diagram.

c. Identify the critical path.

d. If the project needs to be shortened, should managers focus their attention on activity C? Why or why not?

e. Construct a basic Gantt chart for this project.