Top Drawer Teachers

Area in graphs

This is one type of a misleading graph.

Five bars of roughly correct relative height showing amounts $223, $59, $193, $44, $161. The $193 bar is twice as wide as others.

Discussion points

  • What is the title of the graph?

  • What is being represented on the horizontal axis?

  • What is being represented vertically?

  • In a bar graph the area of a bar is proportional to the quantity represented in the bar, so how is this graph misleading?

  • What percentage of the weekly spending is spent on transport?

  • What percentage of the amount spent on transport would the area shown on the graph appear to represent?

  • Why do you think the reporter produced this plot?

  • Explain why we cannot find a median for this data set.

Suggested answers for misleading area graphs can be downloaded.