How were the amounts computed?

Juanita has a business and realizes $300,000 of taxable income or loss over a five-year period as follows: year 1,$50,000; year 2,($30,000); year 3,$100,000; year 4,($200,000); and year 5,$380,000. She is married and files a joint return. Sean also has a business and has a taxable income pattern of $60,000 every year ( $300,000 over the five-year period). He, too, is married and files a joint return. Assuming that there is no provision for carryback or carryover of net operating losses (NOLs), Juanita and Sean would pay the following taxes over the five-year period: Note: The 2023 Tax Rate Schedules are used to compute the tax. Even though Juanita and Sean realized the same total taxable income over the five-year period, Juanita had to pay taxes of $97,439, while Sean paid taxes of only $33,800