Proportional symbols on graphs

Proportional symbols can be added to graphs to show information about different places.

The graph below plots life expectancy against income for each country. It also shows population size. Each country is shown as a circle, where the size of the circle is proportional to the population of the country, i.e. the bigger the circle, the bigger the population of that country.

A proportional symbol graph can use shapes to show comparisons between data points, eg population size of countries plotted on a graph of life expectancy vs GDP per capita.

When interpreting a proportional symbol graph, you should include:

  • the connection between the sets of data on the graph
  • a comparison of the circles in different areas by noting differences between them
  • any visible patterns