Ebling Inc. finances with 0.1 fraction debt, 0.2 fraction preferred and the remaining common stock. Ebeling's before tax cost of debt is 0.05, it cost of preferred stock is 0.12, and its cost of common stock is 0.18. If Ebeling is subject to a 0.4 fraction corporate income tax, what is the company's Weighted Average Cost of Capital?

Please use this formula. Also, is the number negative or positive?

{wd} * {kd} *(1-{Tc}) + {wp} *{kp} + (1-{wd}-{wp})* {ks}

Thanks!