MYP Standard Mathematics Statistical Measures and Data Representation Key Definitions

A chart that displays frequencies for qualitative categories using separated, equal-width bars where bar height represents frequency.

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.

A range of values (such as $20.0 < x \le 20.5$) used to group quantitative data in a frequency table.

Quantitative data that is measured and can take any value within a range (for example, height, mass, temperature).

The running total of frequencies up to a given value or class boundary.

Quantitative data that can be counted or can only take specific separated values (for example, number of goals scored, number of people, shoe size).

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

Frequency divided by class width, used on the vertical axis of a histogram when class widths are unequal.

A frequency table where values are combined into class intervals, and each interval has a frequency.

A graph for quantitative data where values are grouped into class intervals on the horizontal axis, the bars touch, and the bar area represents frequency (or relative frequency).

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.

Non-numerical information that reveals people's thoughts, feelings, and perceptions, often gathered through interviews or observations.

Numerical information that can be measured and recorded, such as height, weight, shoe size, or the depth of a kitchen counter.

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).