To solve for \( H \) in the equation \( \frac{H}{18} = \frac{305}{274.5} \), you can cross-multiply.
- Start by cross-multiplying:
\[ H \times 274.5 = 305 \times 18 \]
- Now, calculate \( 305 \times 18 \):
\[ 305 \times 18 = 5490 \]
- Substitute this back into the equation:
\[ H \times 274.5 = 5490 \]
- Now, solve for \( H \) by dividing both sides by \( 274.5 \):
\[ H = \frac{5490}{274.5} \]
- Perform the division:
\[ H \approx 20 \]
Therefore, the value of \( H \) is approximately \( 20 \).