Arts Architecture Co. has 80,000 bonds outstanding with each selling at par value (par value = $1,000). Bonds with similar characteristics are yielding 6.6 percent. The company also has 4 million shares of common stock outstanding. The stock has a beta of 1.1 and sells for $40 a share. The U.S. Treasury bill is yielding 4 percent and the expected return on the market portfolio is 8 percent. If the tax rate is 34 percent. What is the company's weighted average cost of capital?

Answer: 9.99%

Please explain how to solve this with formulas