Please show me the steps.

Cost 4. Promo Pak has compiled the following financial data: Source of Capital Book Value Market Value Long-term debt $10,000,000 $8,500,000 Preferred stock 1,000,000 1,500,000 Common stock equity 9,000,000 15,000,000 5.0% 14.0 20.0 $20,000,000 $25,000,000 a. Calculate the weighted average cost of capital using book value weights. b. Calculate the weighted average cost of capital using market value weights