Objective and professional context
The synthetic source has North amounts 100 and 200 cents and South 90. The teaching policy releases only groups with at least two observations and omits all individual identifiers. This is a deliberately narrow access/release example, not a legal rule or proof of anonymity. In a real task the data owner must define permitted purpose, audience, retention and review responsibilities.
Your practical assignment
Produce the releasable aggregate and explain a complementary-total attack: what could someone infer if a separate all-region total were also released?
Worked solution and interpretation
North has count 2 and amount 300 cents. South is suppressed. If a total of 390 were also visible, subtraction would reveal South’s amount. The threshold therefore does not establish an anonymity guarantee.
Verification, mistakes and limits
Access filters must apply before aggregation and at export time, not only in a chart. Keep a lineage note linking the view to its source and definition. Review repeated queries and auxiliary data. Risk and privacy claims need evidence and human judgment; this self-practice exercise is not a compliance certification.
Continue with evidence
Keep the unchanged data, your implementation and a changed-input result with a short note explaining what you can and cannot conclude. These free companions do not change saved course progress. The published course catalogue shows deeper assignments available under your current permissions. Keep your conclusions proportional to the evidence you have inspected.
Authoritative reference
Official technical method reference; it does not validate fictional outcomes or your own software environment.
Try the activity before reading its reference. Keep your sources, commands and assumptions with your work. Companion activities are unsaved self-practice and do not award a certificate or change lesson progress.