Total known withholdings = federal + state + FICA + involuntary = (12 + 7 + 7.65) % of 1,375 + Involuntary Net income = gross - withholdings $725.00 = $1,375.00 - [(12 + 7 + 7.65) % of 1,375 + Involuntary] Solve for involuntary 725=1375-0.2665×1,375-inv 725=1375-366.4375-inv Involuntary=1,375−366.4375−725 Involuntary=283.56