Income $72000 - $2160 (401K)= $69,840(taxable income)
Alimony paid $3,600, AGI $66,240
Total home office deductions $1,546,
charitable contributions $1,200. You will not be able to itemized. You will have to take the standard deduction in the amount of $5,350 for a single taxpayer.
AIG $66,240 - $5,350 (standard deduction) - $3,400 (personal exemption) = $57,490 (taxable income) Income tax on $57,490 is $10,797. If you are paid biweekly your employer should be withholding $415.25 for federal income tax.