I need to work out a grading based on a percentage. The higher the percentage, the lower the grading. There are 7 major grades in the score, 1 to 7
(100% = 1) &
(0% = 7)
I need to work out the score value based on the % value. Is there a way to do this? For example: what score between 1 & 7 would 68% be? the 1 to 7 values need to be be point values i.e. 3.87
I cant seem to get the right method
Thanks
Nacho
Best Answer
Assuming you want a linear transformation (and it does not need to be linear), and the two point form is what you need. You have two points: $(100,1)$ and $(0,7)$ The line through them (taking subscript $1$ to be the second point) is $y-7=\frac {7-1}{0-100}x$ or $y=7-\frac 6{100}x$