AP Stats Ch. 3 DEAD Words

Law of Large Numbers

After repeating many trials, the proportion of success will approach the theoretical (expected) probability of success.

Sample Space

A list of all possible outcomes in a scenario/experiment.

Probability

The likelihood of the occurrence of an event (always between 0 and 1).

Complement of an Event

The set of all outcomes of an experiment that are NOT included in an event. (opposite of an event)

Mutually Exclusive

Two events can NOT occur together; therefore, the P(A ∩ B) = 0.

Conditional Probability

A probability based on the assumption that some event has already occurred.

Intersection of Events

The group of outcomes that make two or more events happen at the same time.

Written as: P(A ∩ B)

Union of Events

The event that A occurs or B occurs or both occur.

Written as: P(A ∪ B)

Independent vs Dependent Events

Independent: The probability of one event occurring is UNAFFECTED by the occurrence/non-occurrence of the other events.

Dependent: Events where the outcome of one event CHANGES the probability of another event happening.

General Addition Rule

A method for finding the probability that either OR both of the two events occurs.

Formula: P(A ∪ B) = P(A) + P(B) - P(A ∩ B)

Multiplication Rule

A method for finding the probability that BOTH of two events occurring.

Formula: P(A ∩ B) = P(A) • P(B|A)