Please explain where do 32.5% and 15% come from

Case Study 2 l Question A taxpayer is a single foreign resident individual taxpayer who has taxable income of $15,000 for the 2016-2017 income year. The taxpayer does not have private health insurance. This taxpayer does not hold a visa under class 417 or 462. What is the value of the taxpayer's tax payable or tax refund for the 2016-2017 income year? You are only required to show the value of the answer and to state whether it is tax payable or a tax refund Case Study 2 Answer Answe $4,875.00 The notes below are not required as part of the answer as the question only requires you to write down the answer, but explains the concepts as part of the learning experience: Income Tax payable: = Taxable income x 32.5% = $15,000 x 32.5% $4,875.00 (no tax free threshold for foreign residents). Note: Always show dollars and cents for taxes payable. As the taxpayer is not a resident, they are not liable for the Medicare Levy or the Medicare Levy Surcharge as they don't have access to Medicare benefits