I don't know of an add-in, but Jon Peltier has instructions for creating
Box and Whisker plots:

http://www.peltiertech.com/Excel/Cha...tml#BoxWhisker


Jan Heijs wrote:
> is there an add-inn available that creates a box and whisker plot.
> This a grpahic representaion of statistic information showing the raange of
> values per categorie.


--
Debra Dalgleish
Excel FAQ, Tips & Book List
http://www.contextures.com/tiptech.html