1. The problem statement, all variables and given/known data

Hi all! Having a problem with the ending of this question and I was wondering what I needed to do from here...

The coefficient of rigidity,n, of a wire of lengthLand uniform diameterdis given by

n=AL/d^4

IfAis a constant and the parametersLanddare known to within ± 2% of their correct values, estimate the maximum possible percentage error in the calculated value ofn.

Here is what I have so far...

dn = dn/dL x dL + dn/dd x dd

dn = d/d^4 dL + L/d^4 dd

n = d/d^4 x ΔL + L/d^4 x Δd

n = ΔL/L + Δd/d

Where do I go from here? Any help will be greatly appreciated