StatisticsIntroduction

Measuring How Spread Out Data Is

Part of Range & IQRGCSE Mathematics

This introduction covers Measuring How Spread Out Data Is within Range & IQR for GCSE Mathematics. Revise Range & IQR in Statistics for GCSE Mathematics with 12 exam-style questions and 20 flashcards. This topic appears less often, but it can still be a useful differentiator on mixed-topic papers. It is section 1 of 7 in this topic. Use this introduction to connect the idea to the wider topic before moving on to questions and flashcards.

Topic position

Section 1 of 7

Practice

12 questions

Recall

20 flashcards

Measuring How Spread Out Data Is

Two football teams have the same average age of 25 years. Team A has players aged: 24, 25, 25, 26, 25. Team B has players aged: 18, 22, 25, 28, 32. Which team has more consistent ages?

While both teams have the same mean age, Team A's ages are much more consistent (closer together) than Team B's. We need measures of spread to describe this difference - that's where range and interquartile range come in!

Keep building this topic

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

Practice Questions for Range & IQR

The range of a set of data is calculated by:

  • A. Adding all the values together
  • B. Dividing the total by the number of values
  • C. Subtracting the smallest value from the largest value
  • D. Finding the middle value when ordered
1 markfoundation

Explain why the interquartile range (IQR) is sometimes preferred over the range as a measure of spread.

2 marksstandard

Quick Recall Flashcards

What is the range?
The range is the difference between the highest value and the lowest value in a dataset. Range = Highest value - Lowest value
What are quartiles?
Quartiles are values that divide an ordered dataset into four equal parts: - Q1 (Lower quartile): 25% below - Q2 (Median): 50% below - Q3 (Upper quartile): 75% below

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