Solve the Proportion for the Variable $$\frac { 5 } { 5 z + 3 } = \frac { 2 z } { 2 z ^ { 2 } + 6 }$$

Solve the proportion for the variable. $$\frac { 5 } { 5 z + 3 } = \frac { 2 z } { 2 z ^ { 2 } + 6 }$$ z = __________