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9
11−2.
Class 8 · English Medium · Pearson Edexcel · Mathematics
Data, probability and written reasoning
Compare distributions and probabilities without assuming the same average means identical data.
About this lesson and its coverage
Original Kidemy Class 8 progression. This level has its own text, examples and questions. Curriculum versions share the progression; complete board-specific coverage still needs specification matching and additional material.
Learn the idea
A distribution describes how values are spread. The range is maximum minus minimum and the interquartile range covers the middle half using a stated quartile convention. Conditional probabilities change the reference group.
Worked example
Data1,4,4,7 have mean4 and range6;3,4,4,5 also have mean4 but range2. The means agree while spread differs.
- Identify the quantities and restrictions.
- Show a method with units or symbols.
- Check and explain the result.
Your written practice
Show your working on paper. Check your answer, then choose Next.
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2/5
Two blue out of five.
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1/2
Two blue out of four.
Write in your own words. A guardian or teacher should review this response.
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One ball has been removed, leaving4 possible balls.
Name the updated reference group.
Write in your own words. A guardian or teacher should review this response.
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It depends only on the two extremes and ignores the positions of other observations.
Explain what information is lost.
Progress and browser storage
Notebook challenge, sources and further study
Apply the idea
Construct two datasets with equal means but different ranges and explain both.
Review with a guardian or teacher
- Use the stated evidence or givens.
- Show reasoning rather than only a result.
- Review and explain one correction.
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