The estimated times and immediate predecessors for the activities for Dale Jrs pit crew are given in the following table. Assume that the activity times are independent. To solve this problem, calculate the expected completion time and variance for each activity, draw a network diagram, complete a forward and backward pass, and identify the critical path. Follow the step-by-step solution approach in Gray and Larson text, Chapter 7, Appendix 7.1 called PERT.

What is the probability that this path will be finished in 22 weeks or less?

Your answer should be carried out to two decimal places.

Activity	Immediate predecessor	Time (Weeks)
		a	m	b
A	-	9	10	11
B	-	4	10	16
C	A	9	10	11
D	B	5	8	11