The manager of large computer network has developed following probability distribution of number of interruptions for each day.
|
Interruptions (X)
|
P (X)
|
|
0
|
0.32
|
|
1
|
0.35
|
|
2
|
0.18
|
|
3
|
0.08
|
|
4
|
0.04
|
|
5
|
0.02
|
|
6
|
0.01
|
|
Total
|
1
|
a. Evaluate the expected number of interruptions per day
b. Evaluate the standard deviation.