since a year has 12 months total, 6 months will be 6/12 of a year, thus
[tex]~~~~~~ \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}\dotfill &\$15000\\ r=rate\to 7\%\to \frac{7}{100}\dotfill &0.07\\ n= \begin{array}{llll} \textit{times it compounds per year} \end{array}\dotfill &1\\ t=years\to \frac{6}{12}\dotfill &\frac{1}{2} \end{cases}[/tex]
[tex]A=15000\left(1+\frac{0.07}{1}\right)^{1\cdot \frac{1}{2}}\implies A=15000(1.07)^{\frac{1}{2}}\implies A\approx 15516.12 \\\\\\ \stackrel{\textit{interest yielded}}{~~ \approx ~~ 15516.12~~ - ~~15000} ~~ \approx ~~ 516.12[/tex]
