Irina cashes in Series I Savings Bonde during 2021. She receives $18,755, of which $15,000 was principal and the rest inter Irina uses the proceeds to pay out-of-state tuition and fees totaling $16,500 for her son, whe is a full-time student during the year. She uses the rest of the proceeds to pay for her sons room and board. Irina's filing status is head of household. Irina's only other source of income is her $80,700 salary. Compute Irina's exclusion for Series EE and I interest and her AGI.