1. Chapter 3 Modeling Distributions of Data

2. The standard Normal distribution the Normal distribution with mean 0 and standard deviation 1 z has the standard Normal distribution...

3. On TI-84 Plus C Silver Edition, the area under the standard Normal curve for a z-value can be found by entering the following:

4. Example 1: Joestat hands out cards with z-scores on them. Your job is to find the probability that your neighbor has a lower ranked card. You have a z-score of -.92. Example 2: What is the probability that your neighbor has a higher ranked card? Example 3: Your z-score is -.92 and your neighbors z-score is 1.37. Find the probability that your friend has a card ranked between you and your neighbor. 2nd VARS 2. Normalcdf (-99999,-.92) ENTER 2nd VARS 2. Normalcdf (-.92,-99999) ENTER 2nd VARS 2. Normalcdf (-.92,1.34) ENTER To calculate a probability given a z-score using your TI-84 calculator we use the normalcdf function. normalcdf(Minimum Outcome, Maximum outcome)

5. Set your window settings, by pressing [WINDOW] and setting your values to xmin = - 5, xmax = 5, ymin = -.1 and ymax =.5. Press 2nd VARS (DISTR), scroll right to DRAW, 1:ShadeNorm Enter -99999 as a lower limit,.1 as the upper limit (leave the mean and std dev as default 0 and 1) Pick a color. Press [DRAW]. The probability associated with a Z-score of.1 is shown in the bottom-left corner.

6. And the reverse... Find the z-score for a percentage representing part of the area under a curve. 2nd VARS InvNorm (.7038) ENTER Returns the z-score representing 70.38% of the area under the curve