Question

Explain why correlation doesn't necessarily mean causation on a scatter plot.

Answer 1

A scattered plot represents the correlation between two variables and can have three types of correlation with the plotted variables. It includes positive correlation where the change of one variable accompanies change of the other in same direction, negative correlation where the variables progress in opposite direction and no correlation when there is no impact for one variable on another. But the correlation does not mean that one variable causes change in other variable. There can be another variable playing in the background which causes the change of one variable with respect to another. The scattered plot does not show the third variable which can be the causation and hence we cannot say that the correlation represents causation.