Linear Regression

Question 1

What is simple regression?

Answer 1

Describes the linear relationship between an independent (explanatory) variable and a dependent (response) variable.

Question 2

What is the relationship between an independent variable and a dependent variable?

Answer 2

The independent (explanatory) variable is used to predict values for the dependent (response) variable.

Question 3

What 2 things do we need to know to describe a straight line on a graph?

Answer 3

• Intercept
• Gradient

Question 4

Write the regression equation.

Answer 4

y = b(0) + b(1) x + e(i)

Question 5

How is the line of best fit placed in regression?

Answer 5

Line is placed to minimise the distance between data points and the line (sum of the squared errors).

Question 6

What is the error in regression?

Answer 6

The difference between the observed and predicted value (e).

Question 7

What is the Ordinary Least Squares (OLS) ?

Answer 7

A method for estimating the unknown parameters in a
linear regression model.

Question 8

Give a requirement for using OLS.

Answer 8

Dependent variable must be continuous.

Question 9

What is the purpose of R(2)?

Answer 9

Measures the proportion of the variation in the y variable explained by the model.