Algebra 2 Common Core

$y=4.5$
To find $y$ when $x=3$, set up a proportion using two forms of $\frac{y}{x}$ $\frac{\frac{3}{4}}{\frac{1}{2}}=\frac{y}{3}$ Now write the cross products $\frac{3}{4}(3)=(\frac{1}{2})y$ Simplify $2.25=(\frac{1}{2})y$ Multiply each side by 2 $2(2.25)=(\frac{1}{2})y(2)$ Simplify $4.5=y$