Thundershorse Oil

Thundershorse Oil is a US oil company. Its current cost of debt is 7% and the 10 year US treasury yield, the proxy for the risk-free rate of interest is 3%. The expeced return on the market portfolio is 8%. The company's effective tax rate is 39%. Its optimal capital structure is 60% debt and 40% equity.

A. If Thundershors's beta is estimated at 1.1 what is Thundershorse's weighted average cost of capital?

B. If Thundershorse's beta is estimated at 0.8, significantly lower becasue of the continuing profit prospects in the global energy sector, what is Thundershorse's weighted average cost of capital?