State Refund Worksheet showing key fields for entering prior year tax refund data and filing status.

Based on my analysis of the TS - State Refund Worksheet, I can now explain the solution to this problem.

This worksheet is used to determine how much of a state tax refund received in the current year is taxable on the federal return. The key principle is that if you itemized deductions in the prior year and claimed state income taxes as a deduction, then any state tax refund you receive in the current year may be partially or fully taxable.

Here's the step-by-step solution:

1. Identify the state tax refund amount: The worksheet shows $168 as the "Prior year income tax refund" (from 1099-G).

2. Determine prior year deductions: The taxpayer entered $13,700 as their "Last year's (2014 Tax Return) Standard/Itemized Deductions". This indicates they itemized deductions rather than taking the standard deduction.

3. Consider filing status: The taxpayer was "MARRIED FILING JOINT" in the prior year, which affects the standard deduction amount they could have taken.

4. Apply the tax rule: Since the taxpayer itemized deductions in the prior year (claiming $13,700 in deductions, which is more than the standard deduction for married filing jointly in 2014), part of their state tax refund may be taxable.

5. Calculate taxable portion: The worksheet would typically calculate how much of the $168 refund is taxable based on the benefit received from itemizing deductions in the prior year. However, since the full calculation isn't shown, we can only say that because the taxpayer itemized, some portion of the $168 refund is likely taxable.

6. Special considerations: The taxpayer also claimed the Over 65 deduction last year, which might affect the calculation but doesn't change the fundamental principle that itemizing leads to potential taxability of the state refund.

The solution to this problem is that the taxpayer must report a portion of their $168 state tax refund as taxable income on their federal return because they itemized deductions in the prior year and benefited from deducting state income taxes. The exact taxable amount would be calculated using this worksheet, comparing the refund amount to the benefit received from itemizing in the prior year.

Note: Section 2 is not applicable here since the taxpayer filed as "MARRIED FILING JOINT" rather than "married filing separately."