For example, a model might estimate sales based on age and gender. A regression analysis yields an equation that expresses the relationship. See correlation.

A line chart isn't always helpful in a real-world regression analysis. For example, correlating advertising spending with sales will seldom create a straight line, because today's advertising may ...

A variance inflation factor (VIF) is a measure of the amount of multicollinearity in regression analysis. Multicollinearity exists when there is a correlation between multiple independent ...

Example 55.3: Regression with Quantitative and Qualitative Variables At times it is desirable to have independent variables in the model that are qualitative rather than quantitative. This is easily ...