A company's cost of common equity is 16%, its before-tax cost of debt is 13%, and its marginal tax rate is 40%. Assume that the firm's long-term debt sells at par value. The firm has 576 shares of common stock outstanding that sell for $4.00 per share. Calculate Patrick's WACC using market value weights.

Assets	Liabilities & Equity
Cash $120
Accounts Receivables $240
Inventories $360	Long-term Debt $1,152
Plant and Equip., net $2,160	Common Equity $1,728
Total Assets $2, 880	Total Liabilities & Equity $2,880

The answer is 13.27%

However, I have 12.72%. My equation is WACC=(Market debt weight) x (After-tax cost of debt) + (Market equity weight) x (CAPM cost of Equity) for using market weight values. How do I add stocks into the equation?