MA32-04 Maths Coming soon
Quartiles and interquartile range
MA32-04
This lesson is coming soon.
In this lesson
Calculate the lower quartile, upper quartile and interquartile range from listed data, knowing that each quarter of the ordered data represents exactly 25% of the data count.
What it covers
- Find the lower quartile and upper quartile positions in an ordered list or frequency table
- Calculate the interquartile range as UQ minus LQ
- Drill that each quarter of the ordered data occupies exactly 25% of the data COUNT, not 25% of the value range
Key words
For: AQA GCSE 8300, Edexcel GCSE 1MA1, Edexcel IGCSE 4MA1, Eduqas GCSE C300, Cambridge IGCSE 0580, OCR GCSE J560
On the specification
| Board | Spec | Statement |
|---|---|---|
| AQA GCSE 8300 | S4 | • including box plots |
| Edexcel GCSE 1MA1 | S4 | interpret, analyse and compare the distributions of data sets from univariate empirical distributions through: • appropriate graphical representation involving discrete, continuous and grouped data • appropriate measures of central tendency (median, mean, mode and modal class) and spread (range, including consideration of outliers) |
| Edexcel IGCSE 4MA1 | H6.2B | Understand the concept of a measure of spread |
| Edexcel IGCSE 4MA1 | H6.2C | Find the interquartile range from a discrete data set |
| Edexcel IGCSE 4MA1 | H6.2D | Estimate the interquartile range from a cumulative frequency diagram |
| Eduqas GCSE C300 | HS5 | Interpret, analyse and compare the distributions of data sets from univariate empirical distributions through: appropriate graphical representation involving discrete, continuous and grouped data, including box plots; appropriate measures of central tendency (median, mean, mode and modal class) and spread (range, including consideration of outliers, quartiles and inter-quartile range) |
| Cambridge IGCSE 0580 | E9.3 | Calculate the mean, median, mode, quartiles, range and interquartile range for individual data and distinguish between the purposes for which these are used. |
| Cambridge IGCSE 0580 | E9.6 | Draw and interpret cumulative frequency tables and diagrams. |
| OCR GCSE J560 | 12.03a | Calculate the mean, mode, median and range for ungrouped data. Find the modal class, and calculate estimates of the range, mean and median for grouped data, and understand why they are estimates. Describe a population using statistics. Make simple comparisons. Compare data sets using `like for like' summary values. Understand the advantages and disadvantages of summary values. |
For teachers
This GCSE Maths lesson teaches quartiles and interquartile range. By the end, students should be able to calculate the lower quartile, upper quartile and interquartile range from listed data, knowing that each quarter of the ordered data represents exactly 25% of the data count. It works through two worked examples and the mistakes examiners report.