Northwest Utility Company faces increasing needs for capital. Fortunately, it has an Aa3 credit rating. The corporate tax rate is 35 percent. Northwest's treasurer is trying to determine the corporation's current weighted average cost of capital in order to assess the profitability of capital budgeting projects. Historically, the corporation's earnings and dividends per share have increased about 5.6 percent annually and this should continue in the future. Northwest's common stock is selling at $66 per share, and the company will pay a S8.50 per share dividend (D1). The company's S100 preferred stock has been yielding 10 percent in the current market. Flotation costs for the company have been estimated by its investment banker to be $4.00 for preferred stock. The company's optimal capital structure is 35 percent debt, 15 percent preferred stock, and 50 percent common equity in the form of retained earnings. Refer to the following table on bond issues for comparative yields on bonds of equal risk to Northwest. Data on Bond Issues Moody's Yield to Maturity Rating Price Utilities Southwest electric power-7 1/4 2023 Aa2 905.18 8.34% 893.25 Pacific bell 7 3/8 2025 Aa3 8.93 Pennsylvania power & light 8 112 2022 980.66 8.99 Industrials: Johnson & Johnson 6 34 2023 Aaa 900.24 8.35% Dillard's Department Stores-7 3/8 2023 980.92 8.55 B2 045.10 9.55 Marriott Corp. 10 2015 a. Compute the cost of debt, Ka (use the accompanying table-relate to the utility bond credit rating for yield.) (Do not round intermediate calculations. Input your answer as a percent rounded to 2 decimal places.) Cost of debt