I need help

Let X be a random variable with the following probability distribution. Value x of X P(X=x) -30 0.15 -20 0.15 -10 0.05 0 0.25 10 0.40 Complete the following. (If necessary, consult a list of formulas.) (a) Find the expectation E (X ) of X. E (x) - (b) Find the variance Var(X) of X. Var (x) = 0