To multiply \( \frac{1}{2} \) by \( 3 \), you can treat \( 3 \) as \( \frac{3}{1} \) and then multiply the fractions:
\[ \frac{1}{2} \times \frac{3}{1} = \frac{1 \times 3}{2 \times 1} = \frac{3}{2} \]
So, \( \frac{1}{2} \times 3 = \frac{3}{2} \) or \( 1.5 \) in decimal form.