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Exam Tips for Grouped Data

Part of Grouped Data — GCSE Mathematics

This exam tips covers Exam Tips for Grouped Data within Grouped Data for GCSE Mathematics. Revise Grouped Data in Statistics for GCSE Mathematics with 14 exam-style questions and 20 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 5 of 7 in this topic. Treat this as a marking guide for what examiners are looking for, not just a fact list.

Topic position

Section 5 of 7

Practice

14 questions

Recall

20 flashcards

💡 Exam Tips for Grouped Data

  • Reading intervals: "150 ≤ h < 160" means 150 is included, 160 is not
  • Midpoints: Always (lower boundary + upper boundary) ÷ 2
  • Class width: Should be consistent across all intervals
  • Modal class vs mode: We can only find the modal class, not the exact mode
  • Estimated values: Remember to state that mean and median are estimates
  • Units: Always include units in your final answers
  • Show working: Always show your calculation steps for full marks

Keep building this topic

Read this section alongside the surrounding pages in Grouped Data. That gives you the full topic sequence instead of a single isolated revision point.

Calculating Averages from Grouped DataDifferent Types of Class IntervalsMaking Sense of Large DatasetsKey Facts About Grouped Data

Practice Questions for Grouped Data

A frequency table uses the class intervals shown below. | Speed, s (mph) | Frequency | |---|---| | 0 < s ≤ 20 | 4 | | 20 < s ≤ 40 | 11 | | 40 < s ≤ 60 | 9 | | 60 < s ≤ 80 | 2 | A car travels at exactly 40 mph. Which class interval does this value belong to?

  • A. 20 < s ≤ 40
  • B. 0 < s ≤ 20
  • C. 40 < s ≤ 60
  • D. It could belong to either 20 < s ≤ 40 or 40 < s ≤ 60
1 markfoundation

A teacher groups 30 students' test scores into four class intervals and calculates the estimated mean and estimated median. Explain why both the estimated mean and the estimated median from grouped data are only approximations of the true values. In your answer, refer to the assumptions made.

3 marksstandard

Quick Recall Flashcards

What is class width?
Class width is the size of each class interval. For '10 ≤ x < 20', the class width is 20 - 10 = 10. Equal class widths make data easier to analyze.
What is grouped data?
Grouped data is when individual data values are organized into classes or intervals. For example, heights might be grouped as 150-160cm, 160-170cm, etc.

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Calculating Averages from Grouped Data

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Different Types of Class Intervals