On this page
Begin with matching and units
Read the paired-data lesson and retain a date/period key and return basis. Explain why rotating one list can change beta without changing its separate mean or dispersion.
Reconstruct the fitting calculation
Use centered sums to recover the original 2.1 slope and 1.2% intercept. Check the centroid and residual identities, then calculate the defined R² and residual scale with the appropriate denominator.
Use a progression of questions
| Task | Evidence of understanding |
|---|---|
| Pairing | Matched source identities retained |
| Coefficients | Direction, denominator and units correct |
| Residuals | Observed minus fitted sign retained |
| Basis | Raw/excess definitions explicit |
| Diagnostics | Patterns separated from certification |
| Inference | Additional assumptions identified |
Review why an alternative is wrong
Use the three original practice sets and return to the linked example for any error. The sequence is a learning route rather than a complete official syllabus or a predicted pass result.