[tex]\bf \qquad \textit{Compound Interest Earned Amount}
\\\\
A=P\left(1+\frac{r}{n}\right)^{nt}
\quad
\begin{cases}
A=\textit{accumulated amount}\to &8000\\
P=\textit{original amount deposited}\\
r=rate\to 5\%\to \frac{5}{100}\to &0.05\\
n=
\begin{array}{llll}
\textit{times it compounds per year}\\
\textit{is only once, so}
\end{array}\to &1\\
t=years\to &3
\end{cases} [/tex]
[tex]\bf 8000=P\left(1+\frac{0.05}{1}\right)^{1\cdot 3}\implies 8000=P(1.05)^3\implies \cfrac{8000}{1.05^3}=P\\\\\\6910.70\approx P\implies \stackrel{\textit{rounded up}}{6911 = P}\qquad therefore\qquad 6911~~\leqslant ~~P[/tex]