Yes, the equation \( y = \frac{1}{2} x \) represents a proportional relationship.
In a proportional relationship, the ratio of \( y \) to \( x \) is constant. In this case, for any value of \( x \), if you divide \( y \) by \( x \), you will always get \( \frac{1}{2} \):
\[ \frac{y}{x} = \frac{\frac{1}{2}x}{x} = \frac{1}{2} \]
Since this ratio is constant, we can conclude that \( y \) is directly proportional to \( x \), with a constant of proportionality equal to \( \frac{1}{2} \).