To solve for \( x \) in the equation
\[ \frac{x}{12} = \frac{3}{2}, \]
you can start by multiplying both sides of the equation by 12 to eliminate the fraction. This gives you:
\[ x = 12 \cdot \frac{3}{2}. \]
Now, calculate \( 12 \cdot \frac{3}{2} \):
\[ x = 12 \cdot \frac{3}{2} = \frac{12 \cdot 3}{2} = \frac{36}{2} = 18. \]
Thus, the solution is
\[ \boxed{18}. \]