Box Plot

 

http://www.emeraldinsight.com/journals.htm?articleid=1881783

Box plots are a great tool to show statistical distribution.  The box plot visual is broken up into quartiles with a maximum and minimum data point.  The red box's on the chart above show the majority of the sample group and the line in the middle is the actual average or median of the data collected.  The lines coming from the red box are the maximum and minimum values of data collected.  In this study the girls tested slightly better than the boys in the math test.