Advanced editorial proposal for topic 7, Master 5.2. Fictional monetary units MU, no APEX currency or prices, taxes or investment advice. This is not an approved PRO program.

1. Define period, status and unit of analysis

2. Reconcile sales and returns

3. Compare using the right base and weights

4. Test exceptions and present limits

P3 = missing; cancelled C01 is excluded, not an invented zero sale. Seven rows are not seven sales.

P1 1300−900=400; P2 1300−1020=280; 2600−1920=680. Reconcile rows before comparisons.

A simple SKU average gives 25%, but weighted P1 margin is 30.77%. The base and weights explain why.

Exact repetition counts once; conflict or error stops calculation. Zero net means not calculable; missing means unobserved.

Deliver dictionary, signed reconciliation, weighted comparison and exception log. No real actions.