Marcella (a calendar year taxpayer) purchased a sculpture for $10,500. When the sculpture is worth $26,250 (as later determined by the IRS), Marcella donates it to the Peoria Museum of Art, a public charity. Based on the appraisal of a friend, Marcella deducts $105,000 for the donation. Because Marcella was in the 28% marginal Federal income tax bracket, overstating the deduction by $78,750 results in a tax underpayment of $22,050.

a. Marcella's penalty for overvaluation is $_________?