Unit 4: Statistics and Probability
Topic 4.3: Central Tendency and Spread Questions
Practice 20 exam-style questions for IB Math AA SL Topic 4.3. Review the question stems below, then unlock the full Question Bank to access markschemes, model answers, and AI grading.
1Find3 marks
2026• Aimnova practice — 4.3.1
Find the mean, median and mode of 5, 8, 8, 11, 14, 14, 14.
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2026• Aimnova practice — 4.3.4
A data set has variance 49. State its standard deviation.
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2026• Aimnova practice — 4.3.4
Find the mean and standard deviation of 3, 5, 6, 8, 8, 12 using a calculator.
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2026• Aimnova practice — 4.3.4
Daily temperatures (°C) over a week are 17, 19, 18, 22, 24, 20, 20.
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2026• Aimnova practice — 4.3.1
The mean of 4, 9, x, 12, 16 is 10. Find x.
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2026• Aimnova practice — 4.3.2
Heights are grouped: 140–150 → 4, 150–160 → 9, 160–170 → 14, 170–180 → 8, 180–190 → 5 (40 people). State the modal class.
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2026• Aimnova practice — 4.3.3
A data set has minimum 4, Q₁ = 11, median 16, Q₃ = 23, maximum 35. Find the range and the interquartile range.
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2026• Aimnova practice — 4.3.1
The number of goals in 25 matches: 0 → 6, 1 → 9, 2 → 7, 3 → 3. Find the mean number of goals.
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2026• Aimnova practice — 4.3.3
A data set has IQR 14 and lower quartile 23. Find the upper quartile.
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2026• Aimnova practice — 4.3.4
A data set has mean 30 and standard deviation 5. Every value is increased by 8. Write down the new mean and standard deviation.
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2026• Aimnova practice — 4.3.3
Find the median, Q₁, Q₃ and IQR of 3, 5, 5, 8, 9, 11, 12, 16.
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2026• Aimnova practice — 4.3.4
A frequency table has values 1, 2, 3, 4 with frequencies 6, 9, 8, 7. Find the mean and standard deviation.
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2026• Aimnova practice — 4.3.2
Scores are grouped: 0–20 → 5, 20–40 → 12, 40–60 → 18, 60–80 → 10, 80–100 → 5 (50 students).
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2026• Aimnova practice — 4.3.2
Times (seconds) are grouped: 0–5 → 8, 5–10 → 14, 10–15 → 12, 15–20 → 6 (40 runners). Estimate the mean time.
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2026• Aimnova practice — 4.3.3
A data set has Q₁ = 30 and Q₃ = 50. Determine whether a value of 82 is an outlier.
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2026• Aimnova practice — 4.3.2
Masses (kg) are grouped: 0–4 → 6, 4–8 → 10, 8–12 → 9, 12–16 → 5 (30 items). Estimate the mean mass.
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2026• Aimnova practice — 4.3.3
Eleven house prices (in thousands) are listed in order. State the positions of the median, Q₁ and Q₃.
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2026• Aimnova practice — 4.3.1
A small company has nine salaries (in thousands): 28, 30, 31, 32, 33, 34, 35, 36, 180. State which average best represents a typical salary, with a reason.
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2026• Aimnova practice — 4.3.1
Seven numbers have a mean of 15. Six of them are 10, 12, 14, 16, 18 and 20. Find the seventh number.
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2026• Aimnova practice — 4.3.2
Explain why the mean found from a grouped frequency table may differ from the true mean of the raw data.
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