Given the following: Activity Description Predecessors Duration A Preliminary design 5 B Evaluation of design 1 C Contract negotiation 9 D Preparation of fabrication plant C 7 E Final design B, C 6 F Fabrication of Product DE 12 G Shipment of Product to owner F 3 AU Required: a). Please draw net work b). Calculate all paths and identify critical path c). Calculate Event times (EST & LFT) for this seven-activity project d). Please utilize attached spreadsheet, find out FF & TF for all activities. Identify Zero float activities (Critical path activities). Please check this critical path with manually calculated critical path