The activities of a project and their time estimates are given below :
Activity Estimated duration of activity (in weeks)
Optimistic time (to) Most likely time(tm) Pessimistic time (tp)
1-2 2 5 8
1-4 4 19 28
1-5 5 11 17
2-3 3 9 27
2-6 3 6 15
3-6 2 5 14
4-6 3 6 15
5-7 1 4 7
5-8 2 5 14
6-8 6 12 30
7-8 2 5 8

a) Draw the PERT network Diagram
b) Determine the mean time and standard deviation of each activity
c) Determine the critical path and the standard deviation for the critical path
d) find out the slack for the events
e) find out the total float, free float and independent float for each activity