An observation is considered an outlier if it is more than \((1.5\times \mathrm{IQR})\) below \(\mathrm{Q}_1\) or above \(\mathrm{Q}_3\), where
upper outlier \(= \mathrm{Q}_3 + 1.5 \times \mathrm{IQR}\) lower outlier \(= \mathrm{Q}_1 - 1.5\times \mathrm{IQR}\)

An observation is considered an outlier if it is more than \((1.5\times \mathrm{IQR})\) below \(\mathrm{Q}_1\) or above \(\mathrm{Q}_3\), where

upper outlier \(= \mathrm{Q}_3 + 1.5 \times \mathrm{IQR}\)
lower outlier \(= \mathrm{Q}_1  - 1.5\times \mathrm{IQR}\)

Statistics

International Baccalaureate Mathematics: Applications and Interpretation Standard Level