Amazon has 59,000 shares of common stock outstanding at a market price of $36 a share. The common stock just paid a $1.64 annual dividend and has a dividend growth rate of 2.8 percent. There are 12,000 shares of 6 percent preferred stock outstanding at a market price of $51 a share. The preferred stock has a par value of $100. The outstanding bonds mature in 17 years, have a total face value of $750,000, a face value per bond of $1,000, and a market price of $1,020 each. The bonds pay 8 percent interest, semiannually. The tax rate is 34 percent. What is the firm's weighted average cost of capital?