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Question
Verify whether the following function can be regarded as probability mass function (p.m.f.) for the given values of X :
| X | -1 | 0 | 1 |
| P(X = x) | -0.2 | 1 | 0.2 |
Solution
Here P(X = -1) = - 0.2
i.e. P(X = x) < 0, for x = -1
∴ The function is not a p.m.f.
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