A plant is acquiring new production machinery. Before the machinery can be fully functional, a number of activities must be performed, including rouching out of power, placing the machinery, installing the equipment that will feed product to the machinery etc. The activities, their precedence relationships, and their durations are shown in the following table.

DAYS

Activity	a	m	b	Immediate predecessors
A	8	10	12	----
B	6	7	8	----
C	3	3	6	----
D	10	20	30	A
E	6	7	8	C
F	9	10	11	B, D, E
G	6	7	11	B, D, E
H	14	15	16	F
I	10	11	12	F

J	6	7	8	G, H
K	4	7	10	I, J
L	1	2	6	G, H

(a) Determine the expected times and variances for each activity

(b) Construct a project network for this problem.

(c) Determine the EST, EFL, LST, LFT, and slack for each activity. Also determine the critical path and project completion time.

(d) What is the probability that the project will be finished in 70 days?

(e) What is the probability that the project will need at least 75 days?

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