Activity Immediate Predecessors Normal Expected Duration (days) Variance Crash cost per day A - 3 1 1500 B A 5 2 1200 C A 7 3 1000 D B, C 6 2 1600 E A 9 4 800 F D, E 4 1 2000 The activities of a project and their related information are given in the above table. Each activity can be crashed by at most 2 days. a. Draw the activity-on-node representation of this network using the normal expected durations. b. Determine all the paths of the network and their expected durations. c. Identify the critical path and report the expected project completion time. d. Report the slack values of the activities. e. According to PERT, what is the expected project completion time that we can be 95% confident about? f. If we want to shorten the expected project completion time to 15 days with the minimum crashing cost, how much should we crash each activity?