[tex]\bf \qquad \textit{Amount for Exponential Decay} \\\\ A=P(1 - r)^t\qquad \begin{cases} A=\textit{accumulated amount}\\ P=\textit{initial amount}\dotfill &17100\\ r=rate\to 13\%\to \frac{13}{100}\dotfill &0.13\\ t=\textit{elapsed time}\dotfill &12\\ \end{cases} \\\\\\ A=17100(1-0.13)^{12}\implies A=17100(0.87)^{12}\implies A\approx 3215.34[/tex]