Question

Find the percent of change. $72 to $324

Answer 1

so, from 72 to 324 their difference is 324 - 72 = 252 <-- the change.

if we take 72 to be the 100%, what is 252 off of it in percentage?

$\bf \begin{array}{ccll} amount&\%\\ \cline{1-2} 72&100\\ 252&x \end{array}\implies \cfrac{72}{252}=\cfrac{100}{x}\implies \cfrac{2}{7}=\cfrac{100}{x} \\\\\\ 2x=700\implies x=\cfrac{700}{2}\implies x=350$