AP Statistics: Probability Rules Part 1

Vocabulary flashcards covering foundational probability concepts for AP Statistics, including sample spaces, probability model rules, complements, and mutually exclusive events.

Sample Space ($S$)

The list of all possible outcomes of a random process, denoted with a capital $S$.

Probability Model

A mathematical framework that takes a sample space and pairs each outcome with its probability.

Probability with Equally Likely Outcomes

The calculation determined by dividing the number of outcomes where event $A$ happens by the total number of outcomes in the sample space $S$.

Two Fundamental Rules of Probability Models

The criteria that 1) every individual probability must be a number between $0$ and $1$ inclusive, and 2) the sum of all probabilities across the entire sample space must equal exactly $1$.

Complement of an Event ($A^c$)

The event that event $A$ does not occur, formally denoted using a superscript $c$.

Complement Rule

The principle stating that the probability an event does not occur equals $1$ minus the probability that it does occur: $P(A^c) = 1 - P(A)$.

Mutually Exclusive Events (Disjoint Events)

Events that share no outcomes in common and can never happen at the same time, meaning the probability that both happen simultaneously is $0$.

Addition Rule for Mutually Exclusive Events

The rule used to determine the probability of either event occurring when events cannot occur together: $P(A\text{ or }B) = P(A) + P(B)$.

AP Free Response Question (FRQ) Work Requirement

The scoring standard that requires writing the supporting arithmetic (e.g., an addition sentence) rather than only providing a standalone numerical answer to earn full credit.