# S1 Statistics Revision - Chapter 9 Notes

Chapter 9 - The normal distribution

- Created by: Megan Wilkinson
- Created on: 17-05-12 21:56

First 146 words of the document:

AS Statistics Revision

Statistics 1 Chapter 9

The normal distribution

Key points to remember

The normal distribution = is symmetrical about its mean

has mode, median and mean all equal

ranges from to +

has a total area under the curve of unity

has notation N(, ²) where is the mean and ² is the

variance of the distribution

The standard normal distribution = the standard normal

variable

is denoted by Z where Z ~ N(0, 1²)

Any normal variable X, having a mean and variance ², can

be

transformed into a standard normal variable using:

(X ) ÷

Always remember that the denominator is .

A good clear diagram illustrating the area corresponding to

the

required probability should always be drawn. In the example

the

shaded area shows P(x(1) < X< x(2))

## Comments

No comments have yet been made