The fictitious state of aribraska has a graduated state income tax. residents pay 3% on the first $15,000 of income. the next $25,000 earned is taxed at a rate of 5%. any money earned above $40,000 is taxed at 7%. the income tax for aribraska is modeled by a piecewise defined function. over which part of the domain is the piecewise function defined as f(x) = 0.05x – 300?