Pierre, a cash basis, unmarried taxpayer, had $1,400 of state income tax withheld during 2018. also in 2018, pierre paid $455 that was due when he filed his 2017 state income tax return and made estimated payments of $975 towards his 2018 state income tax liability. when pierre files his 2018 federal income tax return in april 2019, he elects to itemize deductions, which amount to $15,650, including the $2,830 of state income tax payments and withholdings, all of which reduce his taxable income. as a result of overpaying his 2018 state income tax, pierre receives a refund of $630 early in 2019. the standard deduction for single taxpayers for 2018 was $12,000. how much of the $630 will pierre include in his 2019 gross income?