Box and Whisker Plots

Box plot is a tool to visually represent the range, interquartile range, median, mode, outliers, and all quartiles.

A box & whisker plot shows a "box" with left edge at Q1 , right edge at Q3 , the "middle" of the box at Q2 (the median) and the maximum and minimum as "whiskers".

Outliers in Box and Whisker Plots

The standard definition for an outlier is the number which is less than Q1 or greater than Q3 by more than 1.5 times the interquartile range ( IQR=Q3−Q1 ).

An outlier is any number less than Q1−(1.5×IQR) or greater than Q3+(1.5×IQR).