Outliers & Cleaning Data (Edexcel A-Level Mathematics): Quizzes

Data points significantly different from rest

$1.5 \times \text{IQR}$

Greater than $3$ or less than $-3$

$\text{IQR} = Q3 - Q1$

$Q1 - 1.5 \times \text{IQR}$

$Q3 + 1.5 \times \text{IQR}$

$2$ standard deviations

Median is less sensitive to outliers

Mean, median, or mode

Mean of $0$ and SD of $1$

Between $0$ and $1$

Ensure accurate analysis