2. ( 30 points) Consider a project where the activity durations are uncertain. For each activity, we estimate the optimistic time, pessimistic time, and most likely time. The following table provides the information of each activity. a. Determine the critical path by using the pessimistic activity durations. b. Compute the expected duration of each activity. Then, determine the critical path using expected activity durations and compute the variance of project completion time. c. Provide an estimate for the project completion time with 90% probability. Hint: You should compute the z value and provide an estimate as "the project will be completed