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In: Statistics and Probability

Let X be a random variable with the following probability distribution: Value x of X P(X=x)  ...

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

Value x of X P(X=x)  
20   0.35
30   0.10
40   0.25
50   0.30

Find the expectation E (X) and variance Var (X) of X. (If necessary, consult a list of formulas.)

E (x) = ?
Var (X) = ?

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