The data below is for a small ICT project whose time estimates are in weeks. Use it to answer questions that follow.

Activity	Optimistic Time	Most Likely Time	Pessimistic Time
1-2	1	1	7
1-3	1	4	7
1-4	2	2	8
2-5	1	1	1
3-5	2	5	14
4-6	2	5	8
5-6	3	6	15

1. Find the expected time and variance for each activity.
2. Draw the project Network diagram.
3. Find the expected length and the critical path.

What is the probability that the project can be completed 4 weeks before or three weeks after the expected time?