You are tasked with estimating the cost of capital for a firm. The risk-free rate is 4%, the expected rate of return on the market is 15.8%. Now, another similar company (similar unlevered cost of capital) has a debt-to-equity ratio of 1 to 3. It has a debt beta near zero and an equity market-beta of 1.5. Your own firm has more debt, for a debt-to-equity ratio of 1 to 1, with a debt beta of 0.1. What is a good estimate for your firm's cost of capital (WACC)?