What if net profit is less than appropriation

Sales is lower than expenses

I never worked on partnerships, but I guess you got a loss

net Profit minus all interest on capital = loss and this is debited to appropriation accounts. 

Nothing to get surprised about if you get a loss.

if You can attach a screenshot. Interest on capital is calculated at the rate of interest irrespective of whose capital it is. 

Accounting for partnerships | FA2 Maintaining Financial Records | Foundations in Accountancy | Students | ACCA | ACCA Global

The profit sharing ratio is defined here. the profit sharing ratio is used to calculate on residual profits. Simple.