Use the Capital Asset Pricing Model (CAPM).Obtain the stock beta from Yahoo Finance, and the risk-free rate from the US Treasury website, and use it in the CAPM. For Boeing Company

You will need the market value of the common stock outstanding in Phase 6. This is just price per share multiplied by number of shares outstanding.

Use the data you have compiled to calculate the firm's cost of capital = WACC

WACC requires (the market value of the firm's debt , the firm's after-tax cost of debt, the firm's cost of equity & the market value of its common equity)