A 10%, $1,000 semiannual bond is trading at par. The bond's duration is 15 years and its convexity 160 years-squared. Find the bond's volatility in response to a 2% decrease in the yield using second order approximation (i.e with convexity correction). Express your answer as a percentage with 3 (THREE) digits after the decimal point. Omit the % sign.

The correct answer to this problem is 31.475, please show the work and explain why