Activity The Serada IT is installing a new computer system. Several thing must be done to make sure the system is working properly. A list of activities of optimistic, most likely and pessimistic times in weeks are given in the table below. Immediate Predecessors Optimistic (a) Most Likely (m) Pessismistic (b) A 3 4 5 B - 5 8 11 C A 1 9 D B 8 10 18 E A, B 4 6 8 F C, E 4 10 16 G H D F 14 4 15 6 16 8 a) Calculate the expected completion time and variance for each activity (2 decimal). b) Develop a network for this problem. (4 marks) (5 marks) c) Determine the project completion time and the critical path for the installing a new computer system. (2 marks) d) Determine the probability that the project will be finished in 35 weeks. (4 marks)