A project has the below activities:

Activity	Predecessor (s)	To (Weeks)	Tm (Weeks)	Tp (Weeks)
A	-----	4	7	16
B	-----	1	5	15
C	A	6	12	30
D	A	2	5	8
E	C	5	11	17
F	D	3	6	15
G	B	3	9	27
H	E,F	1	4	7
I	G	4	19	28

a) Draw the PERT network.

b) Identify the critical path, and determine the mean project completion times.

c) Find the probability that the project is completed in 36 weeks.

d) If the project manager wishes to be 99% sure that the project is completed, how many days should be provided for the project work.