The independent variable goes on the horizontal axis (x-axis) of a graph. This is because the independent variable is the input or the variable that you control or change in an experiment or function. The dependent variable, which depends on the independent variable, goes on the vertical axis (y-axis). For example, if you are graphing how the amount of time spent studying affects test scores, time would be the independent variable on the x-axis, and test scores would be the dependent variable on the y-axis. This placement helps clearly show how changes in the independent variable affect the dependent variable.