#### Answer

$z=\displaystyle \frac{192}{y}$

#### Work Step by Step

Since we are told that $z$ is inversely proportional to $y$, we have:
$z=\frac{k}{y}$
We are given: $z=12$ and $y=16$, so we have:
$12=\displaystyle \frac{k}{16}$
$k=12*16=192$
Thus the equation is: $z=\displaystyle \frac{192}{y}$