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Question
Choose the correct option from the given alternative:
Find expected value of and variance of X for the following p.m.f.
| X | -2 | -1 | 0 | 1 | 2 |
| P(x) | 0.3 | 0.3 | 0.1 | 0.05 | 0.25 |
Options
0·85
– 0·35
0·15
– 0·15
Solution
Explanation:
E(x) = ∑xipi
E(x) = (-2)(0.3) + (-1)(0.3) + (0)(0.1) + (1)(0.05) + (2)(0.25)
= -0.6 - 0.3 + 0 + 0.05 + 0.5
= -0.35
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