Regression

Question 1

What is an independent variable?

Answer 1

A variable that is set independently of the other variable

Question 2

What is a dependent variable?

Answer 2

A variable whose values are determined by the values of the independent variable

Question 3

What is a residual?

Answer 3

The vertical distance between a data point and the graph of a regression equation

Question 4

What is the regression line?

Answer 4

The line that minimises the sum of the squares of the residuals

Question 5

How can the equation of the regression line of y on x be calculated?

Answer 5

It is y=a+bx, where:

b=Sˣʸ/Sˣˣ
and a=ȳ-bx̄

Question 6

If two variables have been coded, how can the equation of the original variables’ regression line be calculated from the equation of the coded variables’ regression line?

Answer 6

By substituting the method of coding into the equation for the coded variables’ regression line, and then simplifying