|Online Tools » Mathematics » Boxplot|| |
There are many different statistical measures that can be used to describe the values in a data set. To only use one of these measures is often insufficient. Two different data sets can for instance have the same median but still be distributed very differently. It's possible that the values are much more scattered on one side of the median.
A box plot uses multiple different measures to visualize how the values are distributed. The name "box" in box plot refers to the rectangle that is drawn on the number line to show where the quartiles are located. The length of the box is proportional to the interquartile range (i.e. the distance between the lower and upper quartile). The median is marked with a thick line that divides the box into two parts that each contain 25 % of the values. To visualize the whole range the lowest and highest values are drawn as short lines that are connected to the box using yet another pair of lines.
It is possible to compare different data sets by drawing multiple box plots next to each other. All you need to do is to separate the values of each set using three hyphens when entering the values into the text box at the top of this page.