Kelle Carpet and Trim installs carpet in commercial offices. Peter Kelle has been very concerned with the amount of time it took to complete several recent jobs. Some of his workers are very unreliable. A list of activities and their optimistic completion time, the most likely completion time, and the pessimistic completion time (all in days) for a new contract are given in the following table:

	Time (days)	Immediate
Activity	a	m	b	Predecessor(s)
A	3	6	8
B	10	11	12
C	1	2	3
D	7	8	9	C
E	1	3	5	B, D
F	1	2	3	A, E
G	6	9	13	A, E
H	10	11	12	F
I	3	5	7	G
J	14	16	18	C
K	5	9	13	H, I

a) Based on the activity time estimates, the expected times and variance for each of the activities are: