[blueflow]

> In real life the whiskers are the actual minimum and maximum values observed.

Look at this: https://upload.wikimedia.org/wikipedia/commons/1/1a/Boxplot_...

0.7% of all values are outside the whiskers.

[crazygringo]

There are two standard ways of doing box plots. One is miniums and maximums, the other is the 1.5 IQR method.

The very Wikipedia article your image comes from explains this:

https://en.wikipedia.org/wiki/Box_plot#Whiskers