4.1 Scattergraph or Scatter Diagram

A scatter diagram is a method of plotting the values of two variables, using axes and plotting points just as you did for line graphs, but without trying to join any of the points together (this is because usually there are too many dots for any obvious line to be drawn).
The resulting distribution of dots or crosses can then give us an idea of whether the relationship between the two variables is weak or strong.
The technical word for this relationship is correlation, and the calculations and study of correlation form a significant part of many maths and statistics courses. You’ll learn more about this very soon.