To solve the equation \( x^2 = \frac{36}{169} \) by inspection, we need to take the square root of both sides.
Taking the square root of both sides gives:
\[ x = \pm \sqrt{\frac{36}{169}} \]
This can be simplified as:
\[ x = \pm \frac{\sqrt{36}}{\sqrt{169}} = \pm \frac{6}{13} \]
Therefore, the solutions are:
\[ x = \frac{6}{13} \quad \text{and} \quad x = -\frac{6}{13} \]
Thus, the solution set is:
\[ \left{-\frac{6}{13}, \frac{6}{13}\right} \]
The correct solution set is:
\[ { -\frac{6}{13}, \frac{6}{13} } \]