X : 8=15:30

To solve the proportion \( \frac{X}{8} = \frac{15}{30} \), we can cross-multiply: \[ X \times 30 = 8 \times 15 \] Calculating the right side: \[ 8 \times 15 = 120 \] Now, we have: \[ 30X = 120 \] Next, we divide both sides by 30 to solve for \( X \): \[ X = \frac{120}{30} = 4 \] Therefore, \( X = 4 \).