How do I calculate different percentages depending on the amount?

Thanks for the syntax correction, but the formula is still not outputting the correct answer. The percentages should be calculated from each $75,000 payment, but they need to account for the total amount accrued. This is where I am having trouble.

For example:
For the first accrual period ($75,000 in royalties), the inventor should receive $28,750. This is because he gets 40% of the first $50,000 (which is $20,000) and 35% of the remaining $25,000 (which is $8,750). This comes to a total of $28,750. For the next accrual period (again, $75,000 in royalties, now a total of $150,000), the inventor should receive $23,750. This is because he gets 35% for the first $25,000 (which is $8,750), and 30% of the remaining $50,000 (which is $15,000). For the next accrual period (again, $75,000 in royalties) and all subsequent accrual periods, the inventor would only receive 30% of the $75,000 because the total accrued is over $100,000. Does this make sense?