[tex]~~~~~~ \textit{Simple Interest Earned} \\\\ I = Prt\qquad \begin{cases} I=\textit{interest earned}\dotfill &\$45\\ P=\textit{original amount deposited}\dotfill & \$570\\ r=rate\to r\%\to \frac{r}{100}\\ t=months\dotfill &9 \end{cases} \\\\\\ 45 = (570)(\frac{r}{100})(9)\implies \cfrac{45}{(570)(9)}=\cfrac{r}{100}\implies \cfrac{1}{114}=\cfrac{r}{100} \\\\\\ \cfrac{100}{114}=r\implies \stackrel{\%}{0.88}\approx r[/tex]
