# Expectation and Variance of a Random Variable X

Expectation and variance of a random variable

Let X be a random variable with the following probability distribution:

Value x of x P(X=x)

-30 0.35

-20 0.25

-10 0.05

0 0.30

10 0.05

Find the expectation E(X) and variance Var(x) of X.

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#### Solution Summary

The solution is comprised of step-by-step explanations of finding the expectation and variance of a random discrete variable.

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