Answer
$z$ is $\underline{\text{is directly proportional to }} x$;
and $\underline{\text{ inversely proportional }}$ to $y$
Work Step by Step
If $x, y$ and $z$ are related by the equation $z=3\dfrac{x}{y}$, then:
$z$ is directly proportional to $x$ and is inversely proportional to $y$
