2/3:3/4

To simplify the ratio \( \frac{2}{3} : \frac{3}{4} \), you can convert it into a fraction:

\[ \frac{\frac{2}{3}}{\frac{3}{4}} = \frac{2}{3} \times \frac{4}{3} = \frac{2 \times 4}{3 \times 3} = \frac{8}{9} \]

Thus, the ratio \( \frac{2}{3} : \frac{3}{4} \) simplifies to \( 8:9 \).