Glossary — Probability

Combined event — an event that involves two or more stages or outcomes.

Conditional probability — the probability of an event when you know that another event has happened.

Expected frequency — the number of times an outcome is predicted to happen in a given number of trials.

Expected outcome — a result you predict from the probabilities of possible outcomes.

Event — an outcome or group of outcomes that you are interested in.

Frequency tree — a branching diagram that organises counts into groups and subgroups.

Independent events — events where the result of one does not change the probability of another.

Mutually exclusive events — events that cannot happen at the same time.

Outcome — one possible result of an experiment.

Probability — a number from $0$ to $1$ that measures how likely an event is.

Relative frequency — the number of times an outcome occurs divided by the total number of trials.

Sample space — a list of all possible outcomes of an experiment.

Theoretical probability — the probability found from a model of all possible outcomes.

Tree diagram — a branching diagram that shows possible outcomes across stages.

Venn diagram — a diagram that uses overlapping circles to show relationships between sets.