To solve the equation \( \sqrt{2z - 2} = 5 \), we will first square both sides:
\[ (\sqrt{2z - 2})^2 = 5^2 \]
This simplifies to:
\[ 2z - 2 = 25 \]
Next, we add 2 to both sides:
\[ 2z = 25 + 2 \] \[ 2z = 27 \]
Now, we divide by 2:
\[ z = \frac{27}{2} = 13.5 \]
Thus, the value of \( z \) that makes the equation true is \( \boxed{13.5} \).