How to normalize a slope?

Question

Say I have two slopes and two averages for a sample:

$m=4{,}000$ dollars/day, average $a=50{,}000$

$n=80{,}000$ dollars/day, average $b=700{,}000$

Graphically, $n$ is very ‘steep’ compared to $m$. But I know that $n$ is not very steep relative to it's average size ($b=700{,}000$). Is there a way that I could get a ‘percent slope’, so that I could compare the slopes of these two values relative to the average size?

Answer 1

You can simply express this relative change as a fraction, namely

$$\frac ma=0.080=8.0\%\qquad\text{resp.}\qquad\frac nb\approx0.114=11.4\%$$