Hi, I have the following problem.

Data :

Profit Commission
<100 50
101-200 150
201-250 300

However, the commision is not a flat rate but should be given
proportionately within the profit range. E.g. if Net profit is 240, then
commission should be ((300-150)/(250-200))*(240-200)+150 = 270

The formula must be dynamic such that the net profit is variable and once it
changes, the formula has to look up the table to compute the proportionate
commission.