The Tyler Oil Company's capital structure is as follows: Debt Preferred stock Common equity 10% 15 75 The aftertax cost of debt is 6 percent; the cost of preferred stock is 9 percent; and the cost of common equity (in the form of retained earnings) is 12 percent. Calculate Tyler Oil Company's weighted average cost of capital in a manner similar to 2 decimal places.) (Round the final answers to Weighted cost % Debt (Kd) Preferred stock (Kp) Common equity (Ke) (retained earnings) Weighted average cost of capital (ka) %