On complete combustion of 0.492 g of an organic compound containing $\mathrm{C}, \mathrm{H}$ and $\mathrm{O}, 0.7938 \mathrm{~g}$ of $\mathrm{CO}_2$ and 0.4428 g of $\mathrm{H}_2 \mathrm{O}$ was produced. The $\%$ composition of oxygen in the compound is $\_\_\_\_$ .
