# S1 Statistics Revision - Chapter 7 Notes

Chapter 7 - Regression

- Created by: Megan Wilkinson
- Created on: 17-05-12 20:38

First 190 words of the document:

AS Statistics Revision

Statistics 1 Chapter 7

Regression

Key points to remember

Explanatory variable = the variable (usually labelled X) whose

values can be set accurately and which depend only on the

experimenter's choice. Sometimes called the independent

variable.

Response variable = the variable (usually labelled Y) whose

values depend upon the values of the explanatory variable.

Sometimes called the dependent variable.

Scatter diagram = the graph of the pairs of the two variables.

The explanatory variable is plotted horizontally and the

response

variable is plotted variable.

Straight line law = the law of a straight line is given as y=a+bx

where a and b are constants. The gradient of the line is b, and

a

is the intercept on the yaxis (the value of y when x=0)

a is found with:

a = bx

b is found with:

Sxy ÷ Sxx

Interpolation = using the least squares moder to estimate

the

value of the response variable within the original range of

values

of the explanatory variable.

## Comments

No comments have yet been made