AQA GCSE Statistics key terms

The sum of all numerical data values divided by the number of values.

A relationship between variables: their values are connected rather than appearing unrelated.

Using technology to carry out calculations or other processing repeatedly without performing each step by hand.

A measure that summarises the central or typical value of a dataset.

A display with two sets of leaves on opposite sides of shared stems, used to compare two numerical data sets.

A chart in which equal-width, separated bars represent categories or discrete values; each bar’s height represents its frequency or another stated quantity.

A graph showing the frequency of each discrete numerical value using a separate vertical line.

The reference year against which other years are compared; its index number is 100.

A systematic tendency in a collection or analysis method to favour particular outcomes.

A probability distribution for the number of successes in a fixed number of independent trials, each classified as success or failure, with the same probability of success.

The number of births during a stated period relative to the population, commonly expressed as births per 1,000 people per year.

Data consisting of paired values for two variables, with each pair referring to the same person, object or observation.

A diagram summarising a distribution using its median, lower and upper quartiles, and the values shown at the whisker ends.

A method of estimating population size by marking and releasing a first sample, then counting marked individuals in a second sample.

Data consisting of categories or labels, such as favourite colours or types of vehicle.

A relationship in which a change in one variable causes a change in another.

A label identifying a spreadsheet cell by its column letter and row number, such as B2.

An investigation that collects data about every member of a population.

An index comparing a value with the value in the immediately preceding period, rather than with a fixed base period.

A map or spatial diagram in which regions are shaded, coloured or patterned according to the data category they belong to.

A range used to group numerical observations, such as $100 \leq t < 200$ minutes.

The value halfway between the endpoints of a class interval, used to represent observations in that interval when estimating an average.

The difference between the upper and lower boundaries of a class interval.

A question that asks a respondent to choose from a fixed set of response options.

A pie chart in a set of charts whose whole-circle areas are proportional to the totals represented. Sector angles show category proportions.

The event containing all outcomes not in an event $A$, written $A'$.

A chart with bars divided into stacked sections. The whole bar represents a total, and each section represents one component of that total.

The probability of an event occurring when another event is known to have occurred. $P(A\mid B)$ means the probability of $A$ given $B$.