Answer
$\frac{4}{3}$
Work Step by Step
You are given $\frac{a}{b}$=$\frac{3}{4}$
The first Property of Proportions states $\frac{a}{b}$=$\frac{c}{d}$ is equivalent to $\frac{b}{a}$=$\frac{d}{c}$
Simply write the reciprocal. So: $\frac{b}{a}$=$\frac{4}{3}$
