A questionnaire asks only classmates arriving before 8 am. Explain a coverage issue when estimating the whole school’s commute time.
- Use the domain, units and sampling assumptions stated in the question.
Skills and prerequisite lessons
Working and explanation
BUILD THE REASONING
Hint 1
Hint 2
Worked solution
State the survey question, population, sampling and measurement rules before drawing a conclusion.
Calculate or simplify this relation.
More responses within the same restricted frame do not repair that exclusion.
Late-arriving students are excluded and may have systematically different commutes.
Checks and common pitfalls: More responses within the same restricted frame do not repair that exclusion.
Reasoning checklist · self / teacher assessment
- State the relevant definition, condition or model.
- Show a valid calculation, proof or counterexample.
- Interpret the conclusion with its restrictions.
Think first. Reveal a hint when the class is ready.