Correlation is used to describe the linear relationship between two continuous variables (e.g., height and weight). In general, correlation tends to be used when there is no identified response variable. It measures the strength (qualitatively) and direction of the linear relationship between two or more variables.

What is a correlation test used for?

Correlation analysis is used to quantify the degree to which two variables are related. Through the correlation analysis, you evaluate correlation coefficient that tells you how much one variable changes when the other one does. Correlation analysis provides you with a linear relationship between two variables.

How is correlation used in real life?

When an employee works more hours his paycheck increases proportionately. The more gasoline you put in your car, the farther it can go. The longer someone invests, the more compound interest he will earn. The longer amount of time you spend in the bath, the more wrinkly your skin becomes.