Needed answer from A to D. Especially the Pert Network. WILL UPVOTE

CASE APPLICATION Development Project Time Estimates in Days for Each Activity Activity Activity Immediate Designation Predecessor Optimistic Moderate Pessimistic Time Time Time 1-2 10 10 10 1-3 7 10 15 2-4 1-2 8 12 16 3-5 1-3 15 20 25 4-5 2-4, 3-4 7 7 7 F 5-6 4-5, 3-5 4 5 6 G 3-4 1-3 9 11 20 Source of table: Engineering Management, by Dr. Dhilon GUAL Instructions: a) Construct a PERT NETWORK for this project. Project due date is 40days, from now. b) Compute the project probability. (use the table) c) If you are to increase the probability of completion, what is your proposal? d) If there is a problem encountered during the implementation of the project in any of these "resources" (cite a specific resource-problem). As a Project Engineer what are these preparations you must do, so this project won't be dragged to more days delay