the Internal Revenue Code is the top primary source for all US tax legislation. References to tax law is made by identifying certain code sections - for example IRC 501(c)(3) defines charitable organizations. US Federal individual income tax rates are progressive. Please explain what this means and identify the IRC code section that defines individual income tax rates. Make sure to use a proper IRC citation by starting with IRC and then reference the correct #s, lower case letters, upper case letters, etc. and in the correct order. Additionally, calculate the total tax liability and effective and marginal tax rates for a single taxpayer with $250,000 taxable income for 2019 vs. 2020. Use the attached Excel file to complete this calculation and make sure to properly utilize Excel functionality - all of your entries should be formulas and linking. Tax Schedule Comparisons 2019 vs. 2020 Filing Status: Taxable Income: 2019 Tax Schedule: 0 9,700 39,475 84,200 160,725 204,100 510,300 Effective tax rate Marginal tax rate Single 250,000 9,700 @ 39,475 (@ 84,200 @ 160,725 (@ 204,100 @ 510,300 (@ max a 10% 12% 22% 24% 32% 35% 37% 2020 Tax Schedule: Effective tax rate Marginal tax rate 0000000 @ 10% @ 12% @ 22% a 24% @ 32% @ 35% @ 37%