13) Oxy Corporation uses debt, preferred stock, and common stock to raise capital. The firm's capital structure targets the following proportions: debt, 54 %; preferred stock, 10 %; and common stock, 36 %. If the cost of debt is 5.1 %, preferred stock costs 8.7 %, and common stock costs 12.9 %, what is Oxy's weighted average cost of capital (WACC)?

Oxy's weighted average cost of capital (WACC) is ?