George Pays$9300 in tuition and feeding December 2015, and his child began college in January 2016. He filed his 2015 tax return on February 14, 2016, and claimed a lifetime learning credit of $1860. He claimed no other tax credits. After he filed his return, his child withdrew from two courses and George received a refund of $2,900. He must refigure his 2015 lifetime learning credit using $6,400 of qualified education expenses instead of $9,300. After George refigures the credit he determines his tax liability increased by what amount?