Chapter+7

This material will help you review Chapter 7. Defintion of random variable: A random variable is a number attached to a random phenomenon.

Defintion of probability distribution: The values of the random variable are listed with their corresponding probability. X P(x) 0 .2 1 .4 2 .05 3 .2 4 .15

The mean of a probability distribution is found by finding the sum of all the products of each random variable times its probability. The mean of the example probability distribution would be: 0(.2) + 1 (.4) + 2 (.05) + 3 (.2) + 4 (.15) = 1.7