pls i need the answer within 45 mins

To complete the wing assembly for an experimental aircraft, Jim Gilbert has laid out the seven major activities involved. These activities have 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 1 2 3 B 2 3 5 E 2 2 4 5 6 A D 8 9 10 B E 2 00 CD D 4 5 5 2 6 mo 1 3 a. Prepare the network diagram to schedule the activities. b. Identify the critical activities on the diagram. c. Calculate the expected variance of the expected time. d. What is the probability that the project will be completed 18 weeks before its expected completion date? a. Describe your decision