# Expectation and Variance of a Random Variable X

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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.

Â© BrainMass Inc. brainmass.com March 4, 2021, 8:19 pm ad1c9bdddfhttps://brainmass.com/statistics/dispersion-and-spread-of-data/expectation-variance-random-variable-x-160618

#### 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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