Solve the Proportion for the Variable $\frac { 4 } { 4 z + 3 } = \frac { 3 z } { 3 z ^ { 2 } + 9 }$

Short Answer

Solve the proportion for the variable.
$\frac { 4 } { 4 z + 3 } = \frac { 3 z } { 3 z ^ { 2 } + 9 }$
z = __________