Sapp Trucking's balance sheet shows a total of noncallable $$45$ million long$-$term debt with a coupon rate of $7\mathrm{.}00\%$ and a yield to maturity of $5\mathrm{.}12\%.$ This debt currently has a market value of $$50$ million. The balance sheet also shows that the company has $10$ million shares of common stock, and the book value of the common equity $($common stock plus retained earnings$)$ is $$55$ million. The current stock price is $$20$ per share; stockholders' required return, rs$,$ is $17\mathrm{.}97\%$; and the firm's tax rate is $40\%.$ The CFO thinks the WACC should be based on market value weights, but the idiot president thinks book weights are more appropriate. What is the difference between these two WACCs?