What is the relation between these two measures?
If the scales of both relationships are linear then it is very easy to write a linear equation to translate from one scale to the other. You have two points (x,y) from your endpoints as follows. (x being your input value and y being the output value).

(x1,y1) = (7.2, 1.06)
(x2,y2) = (2.5, 1.00)


Knowing that the two point form of a linear equation is:



You can solve that for y in terms of x and arrive at:



(helpful equation solver widget that was used)