These ten questions combine the four skills from the module on data interpretation and limitations: comparing rates, judging samples, wording causal claims and handling missing data. Every town, school, survey and figure is invented for practice.
Attempt each question on paper first, writing your answer as a sentence you could put in an evidence response. Then open the answer and compare the reasoning, not just the number. The questions run from easier to harder.
Questions
1. (Easy) In a fictional table, Clinic A recorded 48 flu visits among 800 residents and Clinic B recorded 30 among 300 residents. Which area has the higher flu-visit rate?
Show answer
A: 48 ÷ 800 = 0.06 = 6%. B: 30 ÷ 300 = 0.10 = 10%. Area B has the higher rate, although A has the higher count.
2. (Easy) In Class P, 9 of 30 students cycle to school. In Class Q, 8 of 20 do. Which class has the larger share of cyclists?
Show answer
P: 9 ÷ 30 = 30%. Q: 8 ÷ 20 = 40%. Class Q has the larger share, even though P has one more cyclist.
3. (Easy) A fictional share of students who own a bicycle rose from 40% to 52%. State the change in two correct ways.
Show answer
It rose by 12 percentage points (52 − 40). In relative terms the rise is 12 ÷ 40 = 0.30, so 30% higher than before. Say which one you mean.
4. (Medium) A fictional website poll asks “Should homework be banned?” Visitors choose to vote, and 85 of 100 voters say yes. Give two reasons the 85% cannot be treated as the view of all students.
Show answer
(1) Self-selection: people with strong views are more likely to vote, and only website visitors were reached. (2) Unknown population: the poll does not say who voted or whether they are students. A fair sentence: “Of 100 voters on one website, 85 said yes; the voters may not represent students generally.”
5. (Medium) Which is stronger evidence about a school of 2,000 students: 150 students chosen by random draw from the register, or 600 students who answered a link sent only to the school sports club? Explain.
Show answer
The random draw of 150. Random selection from the full register gives every student a chance of being included. The 600 are all sports club members, so the group is skewed regardless of size.
6. (Medium) In a fictional study, towns with more street lights have fewer reported thefts. A writer says “Street lights prevent theft.” Give two other explanations.
Show answer
Examples: (a) wealthier or more densely populated towns may install more lights and also have more patrols (a third factor). (b) Towns with fewer thefts may have more resources to spend on lights (reverse direction). Also, theft reporting rates may differ between towns.
7. (Medium) Rewrite so the claim fits the evidence: “Students who eat breakfast get higher marks, so breakfast improves marks.” (Data: one fictional survey of 50 students.)
Show answer
“In one survey of 50 students, those who ate breakfast had higher marks on average; this shows a link, but it cannot show that breakfast caused the difference, because other factors such as sleep or home routine were not measured.”
8. (Harder) A fictional table gives visitors (thousands) to parks: Park X 2022: 40, 2023: 44; Park Y 2022: 55, 2023: not reported; Park Z 2022: 20, 2023: 25. A student writes: “Total 2023 visitors were 89 thousand.” Explain what is wrong and give a correct statement.
Show answer
The student has treated the missing Park Y figure as zero or ignored it: 44 + 25 = 69, and 89 would require inventing a figure for Y (20 thousand). Correct statement: “In 2023, Parks X and Z had 69 thousand visitors in total; Park Y did not report, so a three-park total is unavailable.” Park X rose by 4 thousand and Z by 5 thousand.
9. (Harder) A fictional report says: “Town M has 180 reports of litter, and Town N has 90, so Town M is dirtier.” Town M has 6,000 residents and Town N has 1,500. Evaluate the claim, naming what the report does not tell you.
Show answer
Rates per resident: M: 180 ÷ 6,000 = 3%. N: 90 ÷ 1,500 = 6%. N has the higher rate of litter reports. The report does not say how reports were made, whether residents in each town report equally often, or how much litter each report describes, so “dirtier” is not established.
10. (Harder) A fictional drinks company publishes a survey: “9 out of 10 teenagers prefer our juice.” It asked 10 customers leaving its own shop. Separate the fact, the source’s viewpoint and a fair interpretation.
Show answer
Fact: 9 of 10 shop customers asked said they preferred the juice. Viewpoint: the company wants readers to conclude that teenagers in general prefer it. Interpretation: 10 customers of the company’s own shop are a very small, self-chosen group, so the result may describe loyal customers only and cannot support a claim about teenagers.
If you got these wrong
- Questions 1, 2, 3 or 9 (counts, rates, percentage points): revisit interpreting a small fictional table without confusing counts and rates.
- Questions 4, 5 or 10 (who was asked): revisit recognising an unrepresentative sample.
- Questions 6 or 7 (causal wording): revisit distinguishing association from a justified causal claim.
- Question 8 (gaps in a table): revisit communicating missing data without inventing values.
If one error type keeps appearing across your attempts, that pattern is worth discussing with a teacher. Our online one-to-one Global Perspectives tuition can start from your own answers, and the subject learning guide shows the next topics.