a m E ANSWER ALL QUESTION: To complete wing assembly for an experimental aircraft. Jim Chan has laid out seven major activities involved. These activities has been labeled A through G in the following table, which also shows their estimated completion times (in weeks) and immediate predecessors. Immediate Activity b Predecessors A 2 B 2 3 4 4 D 10 B E 2 5 C.D F 5 G 1 2 3 E 1 3 MUA 6 A 8 9 alool- manna 8 4 6 D a. Determine the expected time and variance for each activity b. Construct the network for the project using PERT. c. Determine the critical path and the project completion time. d. Given that the project variance is 81 week and expected total project time is 62 weeks, what is the probability that the project will be completed 18 weeks before its expected completion date