\[\frac{3x - 4}{6} = \frac{7}{8}\]
\[3x - 4 = \frac{7 \cdot 6}{8}\]
\[3x - 4 = \frac{7 \cdot 3}{4}\]
\[3x = \frac{21}{4} + 4\]
\[3x = \frac{21}{4} + \frac{16}{4}\]
\[3x = \frac{37}{4}\]
\[x = \frac{37}{4 \cdot 3} = \frac{37}{12}\]
\[x = 3\frac{1}{12}\text{.\ }\]