(Extra Credit) 4. A project manager has compiled a list of major activities that will be required to install a computer information system in her firm. The list includes the precedence relationships and estimated completion time for cach activity. (a) Please compute the expected time and standard deviation for each path. (b) what is the probability that the project or will finish in 25 weeks? Activity Immediate Predecessor Time in weeks (Optimistic-Most likely-Pessimistic) 5.9-10 B 6-9-10 A 4-5-6 D 4-6-7 E B 7.9.11 4-5-8 10 F 6-8-10 H DE 5-8-10 End GH