Nonresidents or part-year residents of Arkansas shall compute their taxable income as if all their income was earned in Arkansas, despite the fact that a portion of their income may have been earned in another state or foreign country. Nonresident or part-year residents of Arkansas shall use Arkansas income tax rates to compute their Arkansas tax liability on their taxable income. The computed tax liability is then prorated to Arkansas based on a percentage calculated according to 1. 26-51-435(d).
1.26 Ark. Code R. 51-435(a)&(b)