# Data audit (P1)

File: data/schools.csv, SHA-256 0f1d8378fff2f0898762feaa08dd94d9ad04156dad6330572d98997c9005c88a (matches bundle.json).

• 1000 rows x 4 columns: school_id (int, 100–139), student_id (int, 1–1000, unique), treated (int 0/1), score (float, points, 35.72–64.17, mean 50.80, sd 4.48).
• Missing values: none in any column. Duplicate rows: 0. Duplicate student_id: 0.
• 40 schools, each with exactly 25 students (balanced as stated). treated is constant within every school; 20 treated schools (500 students), 20 control schools (500 students).
• No dates (no date ranges applicable). No anomalies detected; no out-of-range scores evident.
• Information availability: only input is schools.csv, as permitted. No violations.
• Exclusions: none (see out/exclusions.csv).