Social network has 90,000 bonds outstanding that are selling at par. Bonds with similar characteristics are yielding 7.75%. The company also has 580,000 shares of 6% preferred stock and 2.5 million shares of common stock outstanding. The preferred stock sells for $53 a share. The common stock has a beta of 1.34 and sells for $48 a share. The U.S. Treasury bill is yielding 2.6% and the return on the market is 11.2%. The corporate tax rate is 30%. What is the firm's weighted average cost of capital?