Thanks for responding. I went through the program again. Using your example of Delaware Sourced Income, I would insert $3K in the Delaware column for Wages with zeros on the remaining lines. So I'm thinking the only income I should be taxed on as a Delaware non-resident is $3K.......correct?
My retirement income from pension and IRA's is inserted on PIT-NON line 23 (pension/retirement exclusions) so that is subtracted from my federal gross income. When the program calculates my Delaware Adjusted Gross Income (and De taxable income) it still includes any interest, dividends, and capital gains. That amount is much higher than the $3K of Delaware sourced income.
Should the interest, dividends, and capital gains be added to line 23?
No. Being over age 60 your retirement income is excluded from DE adjusted gross income, but interest, dividends and capital gains is not.
DE uses all adjusted gross income which is divided by your DE sourced income to arrive at a ratio. That ratio is multiplied by the tax on the total adjusted gross income to arrive at the tax on the DE source income.
You can see the calculations on line 42 which pulls from lines 30a and 30b.