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Thread: How do you compute the expected value E[X(Y-2)]?

  1. #1 How do you compute the expected value E[X(Y-2)]? 
    Forum Freshman
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    Jul 2013
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    I know that E[Y-2] is equal to E[Y] - 2 but you need the compute the double integral of xy*f(xy) to compute E[XY] what happens to the -2? what about E[A(A+3)], where A is a random variable?


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  3. #2  
    Forum Ph.D.
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    X(Y-2) = XY - 2X, therefore E(X(Y-2)) = E(XY) -2E(X).

    E(A(A+3)) = E(A^2) + 3E(A)


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