How , or is it possible, to write an equation that would basicaly =: If dimensionX is less than 96" outcome should be 36". if dimension X is greater than 120 outcome should be 36, other wise outcome should be 48"

Or: if dimension x is between 96" and 120" outcome should be 36 otherwise outcome should be 48" ?

Jeffrey,

Try this:

"Y"=IIf( "X" < 96,36,IIf( "X" >120,36,48))