#### Answer

$\$358.84$

#### Work Step by Step

According to the Compound Interest Formula, where $P$ is the principal, the amount deposited, $r$ is the annual interest rate, $n$ is the number of times the interest is compounded annualy, $t$ is the number of years, $A$ is the amount the loaner gets back after $t$ years:
$A=P\cdot(1+\frac{r}{n})^{n\cdot t}$
Here we have:
$t=1\frac{1}{2}\text{ years}$
$r=12\%=0.12$
$P=\$300$
$n=12$ (since it is compounded monthly)
Substitute these values into the formula above to obtain:
$A=\$300\cdot\left(1+\frac{0.12}{12}\right)^{12(1.5)}
\\A\approx\$358.84$