Here is some information about Stokenchurch Incorporated:

Beta of common stock $=1\mathrm{.}8$

Treasury bill rate $=4\%$

Market risk premium $=8\mathrm{.}1\%$

Yield to maturity on long$-$term debt $=10\%$

Book value of equity $=$$$500$ million

Market value of equity $=$$$1,000$ million

Long$-$term debt outstanding $=$$$1,000$ million

Corporate tax rate $=21\%$

What is the company's WACC?

WACC: $\_\_\_\_\_\%$