1. Normal Distribution

2. Variance & Standard Deviation
Standard deviation reflects how each data value in the set varies from the mean
On the calculator; STAT→CALC 1: 1-Var Stats σx is the standard deviation
For these Dow Jones monthly gains/losses find the mean and standard deviation
1.38, 0.03, 0.44, 1.06, -0.06, 0.72, 1.58, 1.40, -0.90, -0.19, 0.37, 1.36

3. Standard Normal Curve
A normal distribution with the mean at the center and the data within 3 standard deviations of the mean

4. Example:
In a class the mean test score was a 78 with a standard deviation of 5. Find the range of grades within 1, 2 & 3 standard deviations of the mean.
If you scored a 100 on the test, do you think your grade is an outlier?

5. Histograms and Normal Distributions
Mean height Standard deviation 3.74