Range between values, percentage to value

Question

So I have 2 values:

min: -57 max: 80

I wanna know the value of for example 60%

Sorry if this is simple question but I can't find a solution.

Answer 1

The number that is $x\%$ of the way between the numbers $a$ and $b$ (assuming that $a<b$) is $$a+\left(\frac{x}{100}\right)(b-a)$$ Why? Because $b-a$ is the distance between the numbers $a$ and $b$, so we "start" at the lower number $a$ and "go" $x\%$ (in other words $\frac{x}{100}$) of the total distance to $b$.

So for example, the number that is $60\%$ of the way between $-57$ and $80$ is $$\begin{align*} &\hphantom{=}-57+\left(\frac{60}{100}\right)(80-(-57))\\\\ &=-57+\left(\frac{60}{100}\right)(137)\\\\ &=-57+\frac{8220}{100}\\\\ &=-57+82.2\\\\ &=25.2 \end{align*}$$