To calculate the after-tax cost of debt, multiply the before-tax cost of debt by . Water and Power Company (WPC) can borrow funds at an interest rate of 9.70% for a period of six years. Its marginal federal-plus-state tax rate is 25%. WPCs after-tax cost of debt is (rounded to two decimal places). At the present time, Water and Power Company (WPC) has 15-year noncallable bonds with a face value of $1,000 that are outstanding. These bonds have a current market price of $1,136.50 per bond, carry a coupon rate of 12%, and distribute annual coupon payments. The company incurs a federal-plus-state tax rate of 25%. If WPC wants to issue new debt, what would be a reasonable estimate for its after-tax cost of debt (rounded to two decimal places)? (Note: Round your YTM rate to two decimal place.) 9.17% 7.64% 6.88% 8.79%