OLIVE ntronics is trying to determine its optimal capital structure. The company's capital structure consists of debt and common stock. In order to estimate the cost of debt, the company has produced the following table: Debt-to-total- Equity-to-total- Debt-to-equity Bond B-T cost assets ratio (wa) assets ratio (w) ratio (D/E) rating of debt 0.10 0.90 0.10/0.90 = 0.11 AA 6.0% 0.20 0.80 0.20/0.80 = 0.25 6.6 0.30 0.70 0.30/0.70 = 0.43 A 7.3 0.40 0.60 0.40/0.60 = 0.67 BB 7.9 0.50 0.50 0.50/0.50 = 1.00 B 8.7 The company's tax rate is 35 percent. The company currently has a D/E ratio of 20% and uses the CAPM to estimate its cost of common equity, ks. The risk-free rate is 4.5 percent and the market risk premium is 6 percent. Flashtronics' current levered beta is 1.3. On the basis of this information, what is Flashtronics' weighted average cost of capital (WACC) at its optimal capital structure? Please use two decimal places when completing calculations and show your final answer as a percentage with two decimal places, without the %