# How is the 5-number summary used in constucting a boxplot?

##### 1 Answer

Jan 26, 2015

The 5-number summary gives you the points on the boxplot.

First you put your cases in order of value/score.

*Minimum* (MIN) -- lowest value

*First Quartile* (Q1) -- the value when you reach 25% of your cases.

**Median** (MED or Q2) -- the value of the middle case

*Third Quartile* (Q3) -- when you are at 75% of your cases

*Maximum* (MAX) -- highest value

The 'Box' thus has 50% of all cases.

The picture is in Dutch (Wikipedia), but it should be clear. At the right side it makes the distinction between "largest non-extreme" (the line) and the maximum (the x). Because sometimes it is more realistic to leave some of the extremes out of the picture.