A box plot (Box-and-whisker) plot provides a graphical summary of set of data. In order to draw box plot diagram we should have following information:
  • lower quartile (q1)
  • minimum
  • second quartile or median (q2)
  • third quartile or upper quartile (q3)
  • maximum
Box plot is very useful in showing whether a distribution is symmetric or not. It also helps in finding the distribution of data.

Example*
Draw the box plot diagram for the given information:

Statistic Group A Group B Group C
q1 20 22 30
min 10 15 18
median 40 45 50
max 100 110 90
q3 70 75 57


In Excel 97/2000/2003:

  • Highlight the whole table, including figures and series labels, then click on the Chart Wizard.
  • Select a Line Chart.
  • At Step 2 plot by Rows, (the default is Columns), then Finish.
  • Select each data series in turn and use Format Data Series to remove the connecting lines.
  • Select any of the data series and Format Data Series; select the Options tab and switch on the checkboxes for High-Low lines and Up-Down bars
* This example has been taken from the following webpage:

http://www.coventry.ac.uk/ec/~nhunt/boxplot.htm

References:


Last modified: Wednesday, 10 July 2013, 3:09 PM