Thread: Box and whisker diagram

Hi all,


Im currently trying to revise for a maths skills test, and I'm looking at box and whisker diagrams. So far I've understood it, except one thing. I know the median is the middle value of a given data set, but what do you do if you are asked to draw a box and whisker diagram based on the following:
- The upper quartile
- The lower quartile
- The highest value
- The lowest value


How would you then work out (and apply to the diagram) the median? As I dont see any way of being able to tell how many values are in the data set, just from the information provided above.


I am looking at this website:
Box and whiskers diagram - Schools


Please explain this to me as I'm totally confused.


Thanks in advance!

You cannot determine the median from just the upper quartile, lower quartile, highest value and lowest value. But you can still draw the box which extends from the lower to upper quartile, and the whiskers which extend out from the box to the highest and lowest values.

What you end up with is a box and whiskers plot without the median marked on the box.

.