To find out how many packets of sheet music the chorus students decided to share, we need to calculate \( \frac{3}{8} \) of 24 packets.
We can do this by multiplying 24 by \( \frac{3}{8} \):
\[ \frac{3}{8} \times 24 = \frac{3 \times 24}{8} = \frac{72}{8} = 9 \]
Therefore, the chorus students shared 9 packets.