Question

The distance between the library and town hall is 735 ft the actual distance is 612 ft what is the percent error. Round your answer to the nearest tenth of a percent

Answer 1

well, we know the actual distance is 612, however the estimate is 735, is off by 735 - 612 = 123.

now if we take 612 to be the 100%, what is 123 off of it in percentage?

$\bf \begin{array}{ccll} amount&\%\\ \cline{1-2} 612&100\\ 123&x \end{array}\implies \cfrac{612}{123}=\cfrac{100}{x}\implies \cfrac{204}{41}=\cfrac{100}{x}\implies 204x=4100 \\\\\\ x = \cfrac{4100}{204}\implies x = \cfrac{1025}{51}\implies x \approx 20.098$