The answer is the amount that made it to the Roth IRA. The answer would be $38,000 only if you substituted other funds for the portion withheld for taxes and deposited the entire $38,000 into the Roth IRA. If you did not substitute other funds and only $28,880 made it to the Roth IRA, you did a combination of converting $28,880 and cashing out $9,120.
