## Elementary Technical Mathematics

precision $\frac{1}{5}\ in^2$ GPE $\frac{1}{10}\ in^2$
The smallest unit is $\frac{1}{5}\ in^2$, so that is the precision. Greatest possible error is half the precision. $GPE=\frac{1}{2}\times\frac{1}{5}=\frac{1}{10}$