Question

A random variable X can take on the values 6, -4 and 3 with probabilities 0.45, 0.25 and 0.3 respectively. That is P(X=6) = 0.45, P(X=-4) = 0.25 and P(X=3) = 0.3. Calculate E(X) correct to 2 decimal places.

Answer 1

The expected value, or mean, of the random variable X is 1.60.

Step-by-step explanation:

To calculate the expected value, E(X), we multiply each value of the random variable X by its probability and add the products. In this case, X can take on the values 6, -4, and 3 with probabilities 0.45, 0.25, and 0.30 respectively. Therefore, the expected value is (6 * 0.45) + (-4 * 0.25) + (3 * 0.30) = 2.70 - 1.00 + 0.90 = 1.60.