This graph shows the crime rate comparison in different cities all over the United States. The bubble size is related to the population, while bubble color is related to crime rate.
You could map the symbol size/color to another data set in the Plot Details dialog:
A bubble scale object is added to this graph to display the relationship of bubble size with population. With Linear layout, bubble style as Follow 1st Sybol Style, and Horizontal arrangement, you can customize the bubble chart as above.