Reach for the Star

Sampling and data quality · Optional extension

L045 · Allow 10–15 minutes for learners ready to move on. Answers are available after an attempt.

Stretch

A school has 800 learners, 200 in Year 11. How many Year 11 learners belong in a proportional sample of 64?

Reveal a worked check after attempting

64×200/800=16.

Deep challenge

A survey about canteen food is sent only to the school's sports team. Give two distinct sources of bias and improve selection.

Reveal a worked check after attempting

The team may differ in diet and schedules, and excludes other learners; sample randomly across year groups or strata.

Recall & Review: feedback and extension integration

Lesson L045: Sampling and data quality

Objective: Recognise populations, samples, bias and limits of conclusions.

60-minute structure: 0-7 Connect & Check; 7-14 Share; 14-25 Present/model; 25-44 Apply route choice/practice; 44-52 independent exam-style check; 52-60 Recall & Review, WWW/EBI and next step.

What Went Well (WWW)

I selected an appropriate statistic or representation and supported my comparison or interpretation with specific evidence from the data.

Even Better If (EBI)

I will quote the relevant values or features, compare like with like and explain what the evidence shows without making an unsupported claim.

Stretch and deep challenge

Stretch: A school has 800 learners, 200 in Year 11. How many Year 11 learners belong in a proportional sample of 64?

Deep challenge: A survey about canteen food is sent only to the school's sports team. Give two distinct sources of bias and improve selection.