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Interquartile Range (IQR) Explained
Formula
The interquartile range (IQR) is a measure of statistical dispersion representing the range of the middle 50% of data. It is calculated as Q3 minus Q1 and is resistant to outliers, unlike the full range.
IQR is used to construct box plots and to identify outliers. Values below Q1 - 1.5*IQR or above Q3 + 1.5*IQR are commonly flagged as potential outliers.
Common use cases:
- Identifying outliers in datasets
- Box plot construction
- Robust dispersion measurement
Frequently Asked Questions
Dr. David Park
Applied Mathematician, PhD Mathematics
David holds a PhD in Applied Mathematics from MIT. He has published research on numerical methods and computational algorithms used in engineering and scientific calculators.
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