COMM 215 Lecture Notes - Lecture 6: Random Variable, Standard Deviation, Probability Distribution
Document Summary
Normal probability distribution: a bell-shaped distribution with the following properties: Is unimodal, which means the normal distribution peaks at a single value. Is symmetrical, which means that the two areas under the curve between the mean and any two points equidistant on either side of the mean are identical. The mean, median and mode are equal. The normal approaches the horizontal axis on either side of the mean toward + and - , which means that the normal distribution is asymptotic to the x axis. The amount of variation in the random variable determines the height and spread of the normal distribution. Changing shifts the distribution left or right. Because x is a continuous random variable, the probability p(x) is equal to 0 for any particular x. The probability for a range of values between x and x2 is de ned by the area under the curve between those two values.
