(Cost of debt) The Zephyr Corporation is contemplating a new investment to be financed 33 percent from debt. The firm could sell new $1000 par value bonds at a net price of $910. The coupon interest rate is 13 percent, and the bonds would mature in 14 years. If the company is in a 39 percent tax bracket, what is the after-tax cost of capital to Zephyr for bonds?