# Scaling a scale

I have a list of input values from 0 to 100. Each value must be scaled to a short scale, that start from 20 to 80.

So:

0=>must be 20
100=> must be 80


and each numbers between 0 and 100 must take a scaled value into 20-80 range. What's the formula for scaling this input value?

How about $f(n)=0.6n+20$?.........
• It is the slope-intercept form of a line. You wanted to reduce the range of $100$ to $60$, a factor $0.6$ and you wanted an intercept of $20$. – Ross Millikan Sep 13 '13 at 15:43