It depends.
You are a dual-status alien when you have been both a U.S. resident alien and a nonresident alien in the same tax year. Dual status does not refer to your citizenship, only to your resident status for tax purposes in the United States. In determining your U.S. income tax liability for a dual-status tax year, different rules apply for the part of the year you are a resident of the United States and the part of the year you are a nonresident. The most common dual-status tax years are the years of arrival and departure.
if your income was foreign earned income or passive income earned from investments, you could exclude that portion of the income. Your calculations otherwise look correct.
Here is an IRS link to instructions about the taxation of Dual-Status Aliens.
