Free practice · single-choice · medium
Practice
Handle a missing state without invention
A customer state is blank and no approved source can resolve it. What is the safest analysis-ready value?
Confirmed duplicate · cleaning reconciliation
A controlled removal changes rows and revenue predictably
Row control
Raw4 rows
Clean3 rows
Revenue control
Raw$335
Clean$235
The $100 difference equals the one confirmed extraction duplicate; the raw layer and cleaning log remain preserved.