I have a formula that is simple and the answer is not correct.

I am trying to calculate the payment amount. Because the total overdrawn
amount is not always even, the final payment amount might be different by a
little bit. So here is the formulas that I have entered to get the answer.

Payment Amount: k16/k17
Final Payment Amount: k16 - (K18*(k17-1))

The example I am working with is total overdrawn amt is 535.29 and number of
payments is 6. When I use the calculator, the payments are 89.22 and the
final payment is 89.19. When I use the formula above the final payment is
89.22. The only way I get 89.19 (correct answer) is to type in 535.29-446.10.

What could be the problem?


Total Overdrawn Amount K16
Number of Payments K17
Payment Amount K18
Final Payment Amount K19