Basic Statistical Measures (Edexcel A-Level Mathematics): Flashcards

A statistic indicating position of features (e.g., centre, peak) in data

Measure of location

Sum of

Centre of a data set

$\bar{x} = \frac{\sum x}{n}$

x-bar

Centre of a data set

$\frac{n+1}{2}$

Uses all data

Uses only a single data point

When data has no extreme outliers

Ignores extreme outliers

Median of the lower list

Median of the upper list

$\text{IQR} = UQ - LQ$