Mathematics for IGCSE & O level - Statistical Diagrams (Section 3 - No. 38)
If the interquartile range (IQR) is large, it indicates:
The data is clustered closely together.
The data is spread out over a wider range.
The mean is greater than the median.
The mode is well defined.
Selitys
A large IQR means the middle 50% of the data is spread out.