1. Chapter 9 – The Normal Distribution Math 22 Introductory Statistics

2. Properties of the Normal Distribution Basic properties of all normal distributions:  The total area under the curve is equal to 1  The distribution is bell shaped and symmetric  The curve extends to infinity in both directions  The distribution is centered at the mean  The mean is equal to the median

3. Properties of the Normal Distribution  The area under the curve between any two points of the normal distribution is equal to the probability of observing a value between those two points.

4. z - Score  Number of standard deviations an observation resides from the mean.

5. The Standard Normal Distribution  The mean is equal to 0.  The standard deviation is equal to 1.

6. Finding Probabilities  Finding probabilities using the TI – 83.  Percentiles