Population Regression Line

Definition

The population regression line is a straight line that represents the average relationship between an independent variable and a dependent variable in a population.

Analogy

Think of the population regression line as a blueprint for building houses. It shows the average size and cost relationship between houses in a specific area, helping builders estimate prices based on square footage.

Related terms

Slope: The slope of the population regression line represents how much the dependent variable changes for each unit increase in the independent variable.

Residuals: Residuals are the differences between observed values and predicted values on the population regression line.

Extrapolation: Extrapolation is using the population regression line to make predictions outside of the range of observed data, which can be risky because it assumes that relationships continue beyond what has been observed.