You can use the 2-point form of the equation for a line to work this out. If you have a number between 24 and 75 and you want to find the corresponding percentage, your two points are

(24, 0), (75, 1)

and the equation for the line is

y = (x-24)*(1-0)/(75-24) + 0

y = (x-24)/51

If you want to convert to a percentage, this becomes

If you have a percentage between 0 and 100% and you want to find the corresponding number, solve the above for x.

Y*51/100% = x-24 (divide by the coefficient of x)

(24, 0), (75, 1)

and the equation for the line is

y = (x-24)*(1-0)/(75-24) + 0

y = (x-24)/51

If you want to convert to a percentage, this becomes

**y = (x-24)/51*100%**If you have a percentage between 0 and 100% and you want to find the corresponding number, solve the above for x.

Y*51/100% = x-24 (divide by the coefficient of x)

**x = 24 + 51y/100%**(add 24)