Introduction to Probability

​A number that describes how likely it is that an event will occur.

Probability can be described as a number between 0 and 1.

​Probability

The possible results of an experiment

In the image, the outcomes are red, orange, purple, yellow, and green.

Outcomes

The outcome you want to happen; specified outcomes in an experiment

For example, a favorable outcome in a coin toss would belanding on heads.

Favorable Outcomes

the fraction or percent of the time that an event occurs in an experiment

Relative Frequency

Probability based on comparing the number of possible favorable outcomes to the number of total possible outcomes

Theoretical Probability

Probability based on comparing the number of possible favorable outcomes to the number of total possible outcomes

Experimental probability

The probability of a single event event happening

For example, the probability of picking a green marble is 5/11.

Simple Probability

The probability of 2 or more events happening

For example, the probability of rolling a 6 and spinning a red is 1/24 (1/6 x 1/4)

Compound Probability