Determining Probabilities You have learned the basic concept: about oreos under the normal curve. In this lesson, you wil learn more about ow we continue to explore the normal curve distribution. You have leomed that a wondare normal distribution is a normal distribution with p = 0 and = = 1. You have also leomed that o random vonable with a standard normal distribution, denoted by X, is called a standard normal random vonable. The following notations for random variable are used in our various solution: concerning the normal curve. Mathematical notations are convenient form of lengthy expressions. Plo a] denote: the probability that the I-score is greater than a. P : > of denotes the probability that the s-score is lewer than a Where a and b are I-score values. For example, to denote the area between z = 1 and z = 2, we use the notation: P(1