Question

Sarah deposited $920 into a savings account 6 years ago. The account earns 7 --% interest, compounded annually. How much 3 interest has she earned? Answer in dollars and round to the nearest cent.​

Answer 1

`~~~~~~ \textit{Compound Interest Earned Amount} \\\\ A=P\left(1+(r)/(n)\right)^(nt) \quad \begin{cases} A=\textit{accumulated amount}\\ P=\textit{original amount deposited}\dotfill &\$920\\ r=rate\to 7\%\to (7)/(100)\dotfill &0.07\\ n= \begin{array}{llll} \textit{times it compounds per year}\\ \textit{annually, thus once} \end{array}\dotfill &1\\ t=years\dotfill &6 \end{cases}`

`A=920\left(1+(0.07)/(1)\right)^(1\cdot 6)\implies A\approx 1380.67~\hfill \underset{earned~interest}{\stackrel{1380~~ - ~~920}{\approx 460.67}}`