Question

A sum of $1000 was invested for 4 years, and the interest was compounded semiannually. If this sum amounted to $1448.44 in the given time, what was the interest rate?

Answer 1

$\bf \qquad \textit{Compound Interest Earned Amount} \\\\ A=P\left(1+\frac{r}{n}\right)^{nt} \quad \begin{cases} A=\textit{compounded amount}\to &\ 1448.44\\ P=\textit{original amount deposited}\to &\ 1000\\ r=rate\\ n= \begin{array}{llll} \textit{times it compounds per year}\\ \textit{semi-annually, thus twice} \end{array}\to &2\\ t=years\to &4 \end{cases}$

solve for "r", now, the value you'd get, is a decimal format of it, thus, just multiply it by 100 to get the percent in % form