Programming for a financial application

Question

I have seen it twice now, and I just don't get it. When calculating the "Financial Commission" for a loan with a fixed interest rate, applications force the user to enter all possible loan amounts and related financial expenses. Despite the fact that these rates are calculated (30%), the application makes the user fill in the table as follows:

Loan Amount    Finance Charge    
100            30
105            31.5

etc., while the loan amount is provided from 5 to 1,500 US dollars in increments of 5 dollars.

We are starting a new initiative to restore this system. Is there a good reason to create a betting table this way? I would suggest that we should keep a simple field of interest and compute it every time we need it.

I am really at a loss why someone would hardcode such a table, rather than calculate ... I mean, computers seem to be designed for this kind of thing. Correctly?

Answer 1

It seems like complex interest when you generously round. 100 case + 1 is pretty boring. But an interesting case is 105+.

T[0] = FC[105] => 31.5
T[1] = FC[136.5] => ?

Where are 136.5 hits - 135 or 140? At 140 you made an extra $ 1.05.

Or ... If bets were never settled, that would be one of the reasons for this implementation.

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