1998 Gauss 8 Problem 9

When a pitcher is \frac{1}{2} full it contains exactly enough water to fill three identical glasses. How full would the pitcher be if it had exactly enough water to fill four of the same glasses?

\textbf{(A)}\ \frac{2}{3}\quad \textbf{(B)}\ \frac{7}{12}\quad \textbf{(C)}\ \frac{4}{7}\quad \textbf{(D)}\ \frac{6}{7}\quad \textbf{(E)}\ \frac{3}{4}

If there are no answer choices shown, enter a numerical answer.

Full credit to this problem is given to the CEMC, you may view all Gauss contests here.