[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 &8227\\ r=rate\to 7\%\to \frac{7}{100}\dotfill &0.07\\ t=\textit{elapsed time}\ \end{cases} \\\\\\ A=8227(1-0.07)^t\implies A=8227(0.93)^t[/tex]
