Question

Serena has $130 in her bank account . Her account is compounded quarterly for 2 years at a 9.4% interest rate . What is her total investment after this time period ?

Answer 1

$\bf ~~~~~~ \textit{Compound Interest Earned Amount} \\\\ A=P\left(1+\frac{r}{n}\right)^{nt} \quad \begin{cases} A=\textit{accumulated amount}\\ P=\textit{original amount deposited}\to &\ 130\\ r=rate\to 9.4\%\to \frac{9.4}{100}\to &0.094\\ n= \begin{array}{llll} \textit{times it compounds per year}\\ \textit{quarterly, thus four} \end{array}\to &4\\ t=years\to &2 \end{cases} \\\\\\ A=130\left(1+\frac{0.094}{4}\right)^{4\cdot 2}\implies A=130(1.0235)^8$