Respuesta :
[tex]\bf \qquad \textit{Compound Interest Earned Amount}
\\\\
A=P\left(1+\frac{r}{n}\right)^{nt}
\qquad
\begin{cases}
A=\textit{compounded amount}\to &15000\\
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{annually means, once}
\end{array}\to &1\\
t=years\to &5
\end{cases}[/tex]
solve for "P", to see how much Principal she should deposit today
solve for "P", to see how much Principal she should deposit today
We use the formula for compound growth to figure this problem out. Formula is:
[tex]P=P_{0}(1+\frac{r}{n})^{nt}[/tex]
Where,
- P is the future value
- [tex]P_{0}[/tex] is the initial deposite
- r is the rate of interest annually
- n is the number of times compounding occurs (n=1 for annual compounding, n=2 for semiannual compounding etc.)
- t is time
Given P=15,000, r=5%=0.05 (in decimal), n=1 (since annual compounding), and t=5 years, we can solve:
[tex]15000=P_{0}(1+\frac{0.05}{1} )^{(1)(5)}\\15000=P_{0}(1+0.05)^{5}\\P_{0}=\frac{15000}{(1+0.05)^{5}}\\P_{0}=\frac{15000}{1.05^{5}}\\P_{0}=11,752.89[/tex]
So, Trisha Long needs to deposit $11,752.89 today in the account.
ANSWER: $11,752.89