IB Maths AI 4.2 Definitions

A range of values used to group continuous data, usually written as an interval such as '$40\leq x\lt 50$'.

A running total found by adding successive values as you move through a table or list.

A diagram for grouped continuous data in which each class interval is shown by a touching bar, allowing the shape and spread of the distribution to be seen.

Referring to the middle $50\%$ of the data, between the lower quartile $Q_1$ and upper quartile $Q_3$.

Values that split ordered data into $100$ equal parts; the $p$th percentile has about $p$% of the data below it and can be estimated from a cumulative frequency graph.

Values that split ordered data into four equal parts; on a cumulative frequency graph with $n$ values, they are estimated at cumulative frequencies $\frac{n}{4}$ and $\frac{3n}{4}$.