The following information is for DEF, Inc. a national consumer products company:

Liabilities and Equity	Book values	Target Capital Structure
Notes Payable	$200	1%
Long-term Debt	1,000	10%
Preferred Stock	500	10%
Common equity	4,200	79%

Assume that you are an analyst preparing to calculate DEFs WACC and that the companys target capital structure values above are unknown to you. Further, assume that DEFs cost of debt and cost of equity values are significantly different from each other. How will your estimate of WACC be affected by using weights calculated from the known book values rather than the unknown target capital structure in your calculations?