Consider the network described in the table below.

Activity	Immediate Predecessor(s)	Pessimistic	Probable	Optimistic
J		15	10	8
K		9	8	7
L	J	10	6	5
M	J	3	3	3
N	K,M	9	5	1
O	K,M	10	7	4
P	L,N	10	8	3

Draw the network diagram and answer the following questions. (a) Calculate the expected duration of each activity. (b) Calculate the expected duration and variance of the critical path. (c) Calculate the probability that the project will be completed in more than 28 time units