## Prealgebra (7th Edition)

To determine if a proportion is true, we have to find if the cross products are equal. The cross products of $\frac{a}{b}=\frac{c}{d}$ are $a \cdot d$ and $b \cdot c$. $\frac{4}{5}*9=6*\frac{6}{5} = \frac{36}{5} \rightarrow$ true