please help!!!!!

Uber Technologies, Inc., has a capital structure comprised of 55% debt, 10% preferred stock and 35% common stock. The firm's financial manager finds the estimated before-tax cost of debt is 8% and the estimated cost of preferred stock is 9.2%, and the cost of common stock is 10.6%. What is the firm's weighted average cost of capital? the firm is in the 40% tax bracket. Show your calculation for full credit