# Expected value of a random variable

3. Let X be a discrete random variable with Pr {X = i} = ci for positive, even integers i <= 12; otherwise, the probability is zero, (a) Compute the value of c. (b) What is the mean of X? (c) What is the second moment of X? (d) What is the variance of X? (e) Compute E[(X ? 5)+] where x+ is defined to be max(x,0).

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#### Solution Summary

Discrete random variable and Expected value.

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