=11-19 Tom Schriber, a director of personnel of Management Resources, Inc., is in the process of designing a program that its customers can use in the job-finding process. Some of the activities include preparing resumés, writing letters, making appointments to see prospective employers, researching companies and industries, and so on. Some of the information on the activities is shown in the following table:

Activity Days Immediate a m b Predecessors A 8 10 12 —

B 6 7 9 —

C 3 3 4 —

D 10 20 30 A E 6 7 8 C F 9 10 11 B, D, E G 6 7 10 B, D, E H 14 15 16 F I 10 11 13 F J 6 7 8 G, H K 4 7 8 I, J L 1 2 4 G, H

(a) Construct a network for this problem.

(b) Determine the expected time and variance for each activity.

(c) Determine ES, EF, LS, LF, and slack for each activity.