Basis of Icon Set (conditional formatting) Excel 2007
 

In Excel 2007, new feature of conditional formatting is the "icon set" in
which you can assign an icon on a particular value or range of values. i just
what to know how does the default condition of icon set work? by default,
excel is using the 67% and 33% for 3 iconset but i want to know 67% of what
or 33% of what? how did they compute for that? how did they get it or how did
they compute it? i tried several ways of computing it using the 67% and 33%
but still it doesnt fit the default conditional formatting for icon set. is
it the 67% or 33% of the total of the range or what? im really confused. i
really need to know the answer coz for sure my students will ask me about it.
hope someone can help me about this...

thanks! ^_^