6. please show work thank you.

Builtrite has come up with the following capital structure which management believes is optimal Debt 40% Preferred stock 10% Common stock 50% Bonds: Builtrite is planning on offering a $1000 par value, 20-year, 7% coupon bond with an expected selling price of $1025 Flotation costs would be $55 per bond. Preferred Stock: Builtrite could sell a $46 par value preferred with an 8% coupon for $38 a share. Flotation costs would be $2a share. Common stock: Currently, the stock is selling for $62 a share and has paid a $2.82 dividend. Dividends are expected to continue growing at 10%. Flotation costs would be $3.75 a share and Builtrite has $350,000 in available retained earings. Assume a 40% tax bracket. What is the after-tax cost of debt? 4.38% O 5.60% 7.30% 9.34%