A new European-style floating lookback call option on a stock index has a maturity of 9 months. The current level of the index is 400 , the risk-free rate is $6 \%$ per annum, the dividend yield on the index is $4 \%$ per annum, and the volatility of the index is $20 \%$. Use the approach in Section 27.5 to value the option and compare your answer to the result given by DerivaGem using the analytic valuation formula.