State tax filing

Yes, there's a detail worksheet that calculates the figure for line 3. It's called Other Interest and Dividends Included Statement. See the image below.

If you are using TurboTax Desktop, you can view it in Forms mode and find out where this line 3 figure is coming from. To use Forms mode, select the Forms icon in the upper right corner, then highlight the form you want to see in the list on the left. 

If you are using TurboTax Online, you will need to print or preview the return with all worksheets to find this form. 

If you have more questions after viewing the worksheet, reply back and TurboTax can help you further.