Thunderhorse Oil. Thunderhorse Oil is a U.S. eil compary. lis current cost of debt is 7.50%, and the 10-year U.S. Treasury yeld, the proxy for the risk.tree rate of interest is 3.40%. The expected retuen on the matket portlolio is 790%. The company's effective tax rate is 30%. its eotimal capital structure is 45% debt and 55% equity. a. It Thunderhorse's beta is estmated at 0.90 , what is Thunderhorse's weighted average cost of eapiar? b. If Thunderhorse's bets is estimated at 0.50 , significantly lower because of the continuing proft prospects in the global energy sector, what is Thunderhorse's weighted average cost of captal? a. If Thunserherse's beta is estimated at 0.90, what is Thunderhorse's weighted average cost of eaptar? 6 (Round to two docimal places )