Lightning, Inc. has a target capital structure of 60 percent common stock, 20 percent preferred stock, and 20 percent debt. Its cost of equity is 12 percent, the cost of preferred stock is 5 percent, and the pretax cost of debt is 9 percent. The relevant tax rate is 21 percent. What is the aftertax cost of debt in percent? Round to two places past the decimal point. Numeric Response