A firm has $6.9 Billion debt outstanding, with a yield to maturity of 5.8% and a coupon rate of 4.2%. They have 183 million preferred shares outstanding, currently trading at $82.51. They also have 741 million common shares outstanding, currently trading at $40.86 and the corporate tax rate is 22%. If the return on common stock (return on equity) is 9.1% and the return on preferred stock is 6.5% what is the Weighted Average Cost of Capital (WACC)