#### Answer

The missing length is 13.5 units

#### Work Step by Step

$\frac{9}{z}$=$\frac{15}{22.5}$ set cross products equal
15z=9$\times$22.5
15z =202.5 divide by 15 both sides
$\frac{15z}{15}$=$\frac{202.5}{15}$
z=13.5
The missing length is 13.5 units