Lesson 2.02j

2.02j Cleaning data and missing values Quiz: OCR Maths, Unit 12

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

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Lesson 2.02j, Cleaning data and missing values: 20 multiple choice questions for the OCR Maths (H240), Unit 12: Data Presentation and Interpretation, written with Revision Ninja.

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The 20 questions

  1. Which formula gives the lower outlier boundary using interquartile range?

    • Q1 - 1.5 × SD
    • Q1 - 1.5 × IQR
    • Q3 - 1.5 × IQR
    • Q1 - 2 × IQR

  2. Which formula gives the upper outlier boundary using interquartile range?

    • Q3 + 1.5 × IQR
    • Q3 + 1.5 × SD
    • Q1 + 1.5 × IQR
    • Q3 + 2 × IQR

  3. Which formula gives the upper outlier boundary using standard deviation?

    • Mean + 1.5 × SD
    • Median + 2 × SD
    • Mean + 3 × SD
    • Mean + 2 × SD

  4. Which formula gives the lower outlier boundary using standard deviation?

    • Mean - 3 × SD
    • Mean - 1.5 × SD
    • Median - 2 × SD
    • Mean - 2 × SD

  5. If Q1 is 10 and Q3 is 20, what is the lower outlier boundary?

    • -10
    • -5
    • 5
    • 0

  6. If Q1 is 12 and Q3 is 24, what is the upper outlier boundary?

    • 48
    • 42
    • 36
    • 30

  7. A dataset has mean 50 and standard deviation 8. What is the upper outlier threshold?

    • 74
    • 62
    • 66
    • 58

  8. A dataset has mean 40 and standard deviation 5. What is the lower outlier threshold?

    • 30
    • 25
    • 20
    • 35

  9. What term describes the process of removing or correcting erroneous data values?

    • Data cleaning
    • Data extrapolation
    • Data regression
    • Data sampling

  10. What is an extreme data value that differs significantly from other observations called?

    • Outlier
    • Parameter
    • Residual
    • Variance

  11. How should an obviously impossible recorded value, such as a negative height, be handled?

    • Double the value
    • Keep unchanged
    • Remove or correct
    • Replace with zero

  12. Why are median and IQR preferred over mean and standard deviation for skewed data?

    • Always give zero
    • Resistant to outliers
    • Ignore middle values
    • Easier to calculate

  13. In a dataset with Q1 = 10 and Q3 = 18, is 32 considered an outlier?

    • Cannot be determined
    • Yes, below threshold
    • Yes, above threshold
    • No, within limit

  14. What is a common method for handling a single missing numerical value in cleaning?

    • Deleting entire dataset
    • Mean imputation
    • Setting to infinity
    • Linear regression

  15. If a high upper outlier is removed from a dataset, what happens to the mean?

    • Increases
    • Decreases
    • Becomes zero
    • Stays the same

  16. How does removing an extreme outlier affect the standard deviation of a dataset?

    • It becomes negative
    • It increases
    • It stays unchanged
    • It decreases

  17. What happens to the median when the maximum outlier is removed from a dataset?

    • Shifts slightly lower
    • Increases significantly
    • Stays strictly identical
    • Doubles in value

  18. For mean 100 and standard deviation 15, is 135 considered an outlier?

    • Yes, above boundary
    • Yes, below boundary
    • No, below boundary
    • No, on the mean

  19. Which statistical diagram explicitly shows outliers as individual points beyond its whiskers?

    • Pie chart
    • Box plot
    • Cumulative frequency
    • Histogram

  20. Given Q1 = 5 and Q3 = 8, what is the maximum non-outlier value threshold?

    • 14.0
    • 13.5
    • 12.5
    • 11.0

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