MYP Standard Mathematics Univariate Statistics Key Definitions

A diagram that displays the five-number summary using a box from $Q_1$ to $Q_3$, a median line, and whiskers extending to the minimum and maximum (or to the most extreme non-outlier values, depending on convention).

Data grouped into categories or labels (for example, eye color, type of transport). Arithmetic operations like averaging are not meaningful.

The overall pattern of a data set, including its center, spread, and shape (for example, symmetry, skewness, clusters, and gaps).

The spread of the middle 50% of the data: $\text{IQR}=Q_3-Q_1$.

The arithmetic average of a data set, found by adding all values and dividing by the number of values.

The middle value when the data set is ordered. If there are two middle values, the median is their average.

Data measured or counted as numbers (for example, height, time, number of siblings). Numerical data can be summarized using measures such as mean and quartiles.

A data value that lies an unusually large distance from the rest of the data set.

Values that split an ordered data set into four equal parts: $Q_1$ (lower quartile), $Q_2$ (the median), and $Q_3$ (upper quartile).

A display that organizes numerical data by separating each value into a stem and a leaf, allowing the original data values to be reconstructed.

Data consisting of observations of a single variable for each individual or item (for example, one height measurement per student).