Recall that the expected value is calculated using the formula = xP(x), where x is the value of a random variable, P(x) is the probability of that variable, and the sum is taken for all values of the random variable. First determine xP(x), the product of x and P(x), for each value of x (let x = 4 for the value of "at least 4"). x 0 1 2 3 at least 4 P(x) 0.48 0.32 0.16 0.03 0.01 xP(x) 0(0.48) = 0 1(0.32) =