I need assistance with problem c. there are two parts the before-tax cost of debt and after-tax cost of debt.

Cost of debt usirg both methods (YTM and the approximation formula) Currently, Warren Industries can sell 15-year, $1,000-par-value each before incurring flotation costs of $35 per bond. The firm is in the 30% tax bracket. s paying annual interest at a 12% coupon rate. As a result of current interest rates, the bonds can be sold for $980 a. Find the net proceeds from the sale of the bond, Nd b. Calculate the bond's yield to maturity (YT) to estimate the before-tax and after-tax costs of debt. c. Use the approximation formula to estimate the before-tax and after-tax costs of debt. a. The net proceeds from the sale of the bond, Nd is $ 945. (Round to the nearest dollar.) b. Using the bond's YTM, the before-tax cost of debt is 12.84 %. (Round to two decimal places.) Using the bond's YTM, the after-tax cost of debt is 8.99 %. (Round to two decimal places.) c. Using the approximation formula, the before-tax cost of debt is | %. (Round to two decimal places.)