3.19 Kelle Carpet and Trim installs carpet in commercial offices. Peter Kelle has been very concerned with the amount of time it took to complete several recent jobs. Some of his workers are very unreliable. A list of activities and their optimistic comple- tion time, the most likely completion time, and the pessimistic completion time (all in days) for a new contract are given in the following table: TIME (DAYS) ACTIVITY A AB B 3 2 E IMMEDIATE PREDECESSOR(S) C 1 642 00 43 B DEF 6 7 00 C 2 4 6 B. D 6 10 14 A, E G 1 2 4 A, E H 3 3 6 LO 9 LL 10 11 12 G J 14 16 20 C K 2 8 CO 10 H, I a) Determine the expected completion time and variance for each activity. b) Determine the total project completion time and the critical path for the project. c) Determine ES, EF, LS, LF, and slack for each activity. d) What is the probability that Kelle Carpet and Trim will finish the project in 40 days or less? P