Math
Outliers.
Definition
Data points that are significantly different from the rest of the dataset. A common rule identifies outliers as values more than 1.5 times the interquartile range (IQR) below Q1 or above Q3.
Examples
Real-world.
- 1 In test scores of 85, 88, 90, 92, 45, the score of 45 is an outlier
- 2 A salary of $2 million in a dataset of middle-class incomes
- 3 A 7-foot-tall student in an elementary school class
Key Fact
Outlier if value < Q1 - 1.5(IQR) or value > Q3 + 1.5(IQR)