7.PS.1 Probability Study Guide

Vocabulary flashcards covering core definitions, formulas, likelihood scale values, and foundational principles from the 7.PS.1 Probability Study Guide.

Probability

The study of chance and prediction.

Trial

A single test with more than one possible result.

Outcome

A possible result of a trial.

Experiment

Repeating a trial multiple times.

Sample Space

The list of all possible outcomes of a trial.

Events

A way to group outcomes (such as all even numbers).

Fair

A condition in which every outcome has an equal chance of happening.

Theoretical Probability

What should occur in an experiment, defined by the formula: $P(\text{event}) = \frac{\text{number of FAVORABLE outcomes}}{\text{number of POSSIBLE outcomes}}$

Experimental Probability

What actually occurs during an experiment, defined by the formula: $P(\text{event}) = \frac{\text{number of FAVORABLE outcomes that occur during a trial}}{\text{TOTAL number of TRIALS performed}}$

Impossible

A likelihood scale rating corresponding to a numerical value of $0$ (or $0\%$), such as rolling a 7 on a standard 6-sided die.

Unlikely

A likelihood scale rating corresponding to a numerical value greater than $0$, but less than $\frac{1}{2}$ (or $1\% - 49\%$), such as winning a raffle with 1 ticket out of 100 sold.

Equally Likely

A likelihood scale rating corresponding to a numerical value of $\frac{1}{2}$ (or $50\%$), such as flipping a fair coin and landing on Heads.

Likely

A likelihood scale rating corresponding to a numerical value greater than $\frac{1}{2}$, but less than $1$ (or $51\% - 99\%$), such as pulling a red marble from a bag of 8 red and 2 blue marbles.

Certain

A likelihood scale rating corresponding to a numerical value of $1$ (or $100\%$), such as the sun rising in the east tomorrow.

Law of Large Numbers

The principle stating that as the number of trials increases, the experimental probability gets closer to the theoretical probability.