Edexcel GCSE Statistics · 1ST0
Specification 2a.01, 2a.03, 2a.07, 2c.01, 2c.02, 2c.03, 2c.04, 2c.05 · Paper 1, Paper 2
The difference between the upper and lower quartiles, describing the spread of the middle half of a data set.
Revise: Pictorial data representationFor example, a second group with a median reduction of 26 mmHg and an interquartile range of 12 mmHg would have a greater typical reduction and less variation in its middle half than this group. This describes the recorded results; it does not by itself establish why the groups differ.
The difference between the upper and lower quartiles: . It describes the spread of the middle 50% of the data.