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 8 in this topic. Use this introduction to connect the idea to the wider topic before moving on to questions and 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!
Practice questions for Range & IQR
The range of a set of data is calculated by:
Explain why the interquartile range (IQR) is sometimes preferred over the range as a measure of spread.