# Contract (P0) — F1-conf-04

Question. Summarise the provider's property-sales export (data/sales.csv) and reconcile it to provider control totals (data/metadata.json). Estimands (over records readable unambiguously from the file): n_valid_records; sum and mean of price_cad; median of price_cad/area_m2; reconciliation of count and price sum to controls (n_unreadable = control − valid; implied unreadable sum = control sum − valid sum). Meaningful assuming control totals describe the same table before export and that readable records are exported faithfully. Outputs. out/results.json (task_id, n_records_control, n_valid_records, n_unreadable_records, n_analysed, sum_price_control, sum_price_valid, sum_price_unreadable_implied, mean_price_valid, median_price_per_m2_valid, feasibility, feasibility_reason, data_issues, n_input_rows, random_seed); out/analytic.csv; out/exclusions.csv; out/report.md; out/analysis.py; out/claims.json; plus state files. Information rules. Only data/ files. No reconstruction/imputation/guessing of unreadable records. feasibility "complete" only if all control records are analysed; else "partial" with exact count and reason. Invalidity. Imputing corrupted rows; using external information; counting the same record twice; misparsing quoted fields.