Adjusted WACC. Clark Explorers, Inc., an engineering firm, has the following capital structure: : Using market value and book value (separately, of course), find the adjusted WACC for Clark Explorers at the following tax rate a. 40% b. 30% c. 15% d. 10% Market Price Outstanding units Book value Cost of capital Equity $71.19 140,000 $2,524,000 17.13% Preferred Stock $94.62 12,000 $1,054,000 11.98% Debt $1098.79 5,384 $5,384,000 9.2%