At a taxable income of $80,000 adam's income tax is $18,400. when his taxable income rises to $90,000 his income tax is $21,000. based on this information, adam's marginal tax rate is _____________ percent and his new average tax rate is ____________ percent. 3.8; 23.0 23; 26.0 26; 23.3 18; 24.0 21; 23.3