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Question
A random variable X has the following probability distribution:
then E(X)=....................
Options
0.8
0.9
0.7
1.1
Solution
(a) 0.8
|
X = x |
-2 |
-1 |
0 |
1 |
2 |
3 |
|
P(x) |
0.1 |
0.1 |
0.2 |
0.2 |
0.3 |
0.1 |
`E(X)=sumx_iP(x_i)`
=( -2) x 0.1 + ( -1) x 0.1+ 0 x 0.2 +1x 0.2+ 2 x 0.3 + 3 x 0.1
= - 0.2 - 0.1 + 0 + 0.2 + 0.6 + 0.3
=0.8
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