1) GreenTech is managing a solar panel installation project for a commercial building. The project manager, Lisa Green, is concerned about delays because some tasks have unpredictable durations. The following table shows the optimistic time (a), most likely time (m), and pessimistic time (b) for each activity (all in days), along with their immediate predecessors:a) Calculate the expected time and variance for each activity using the PERT formulas: b) Construct the project network and determine the expected project completion time and the critical path. c) Compute the expected values for Earliest Start (ES), Earliest Finish (EF), Latest Start (LS), Latest Finish (LF), and slack for each activity. d) Assuming activity durations are independent and normally distributed, calculate the probability that the project will finish in 44.0 days or less.