Consider following data of a project. Duration (weeks) Activity Predecessor a m b A - 1 2 3 B - 2 2 8 C A 6 7 8 D B 1 2 3 E A 1 4 7 F C,D 1 5 9 G C,D,E 1 2 3 H F 1 2 9 Based on above information, (a) Construct the project network. (b) Find the expected duration and variance of each activity. (c) Find the critical path and expected project completion time. (d) What is the probability of completing the project on or before 20 week. Take P(z1.542) =0.9382.