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Thread: expected and variance

  1. #1
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    expected and variance

    Expectation and variance of random variable
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  2. #2
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    1)To find the expected value simply find $\displaystyle \sum xp(x)$

    2)Not sure how to find the Variance.
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  3. #3
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    Expected value: $\displaystyle E(X) = \sum\limits_{x \in X} {xP(x)} $.

    Variance: $\displaystyle V(X) = E\left( {X^2 } \right) - \left[ {E(X)} \right]^2 = \sum\limits_{x \in X} {x^2 P(x)} - \left[ {E(X)} \right]^2 $
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