Loading...
A Normal distribution is described by a Normal density curve Any particular Normal distribution is completely specified by two numbers: its mean ???? and its standard deviation ???? The mean of a Normal distribution is the center of the symmetric Normal curve The standard deviation is the distance from the center to the change-
Normal Distribution (Characteristics) Horizontal Axis = possible X values Vertical Axis = density (i e f(X) related to probability or proportion) Defined as The distribution relies on only the meanand s ( ) ( )1( ) 22 2 2 f X eXµ ? ? ? =? ? ( ) *(2 71828183)1( ) 22 2 ( ) 2*(3 14159265) X X si f Xi s Psy 320 - Cal State Northridge 4
Section 1 3: The Normal Distribution Learning goals for this chapter: Know when and how to use the empirical (68-95-99 7 rule) Understand what the standard Normal distribution is and how it is related to other Normal distributions Calculate both forwards and backwards Normal distribution problems
standard normal distribution chart How to use the Standard Normal Distribution Table: The standard normal distribution table is shown in the back of your textbook The first column (up and down) of the table represents the number to the left of the decimal of the z-score and the first number to the right of the decimal of z-score
have a normal distribution • The normal distribution is easy to work with mathematically In many practical cases, the methods developed using normal theory work quite well even when the distribution is not normal • There is a very strong connection between the size of a sample N and the extent to which a sampling distribution approaches