\begin{equation*} 0.3 - 1.645 \sqrt{\frac{0.3 \cdot 0.7}{100}} \lt p \lt 0.3 + 1.645 \sqrt{\frac{0.3 \cdot 0.7}{100}} \end{equation*}

\begin{equation*} 0.225 \lt p \lt 0.375. \end{equation*}