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

Data points significantly different from rest of data

Outside $1.5 \times \text{IQR}$ above $Q3$ or below $Q1$

$Z > 3$ or $Z < -3$

$\text{IQR} = Q3 - Q1$

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

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

Addressing issues in data for accurate analysis

Median

Mean, median, or mode

Mean of $0$ and standard deviation of $1$

Between $0$ and $1$

$2$ standard deviations from mean

$\bar{x} \pm 2\sigma$