**Contents**

### Explanatory Variable

- The
**explanatory variable (EV)**is the variable used to**explain or predict**another variable (the response variable). - By convention, the explanatory variable is plotted along the x-axis of a graph, if it is numerical.

### Response Variable

- The
**response variable (RV)**is the variable which is explained or predicted by the explanatory variable. - By convention, the response variable is plotted along the y-axis of a graph, if it is numerical.

Note: both explanatory and response variables can be either categorical or numerical variables.