Probability

Definitions

**Probability**: The chance or
likelihood that an event will occur. It is usually expressed as a
fraction, but can be given as a decimal or percent.

A **Probability of 0** means that the
event can **never** occur (for example rolling a 0 on a six-sided dice
numbered 1-6)

A **Probability of 1** means that the
event will **always** occur (for example rolling a number on a six-sided
dice)

**Experimental Probability**: The
probability of an event based on the **results** of an **experiment**.

For example: If I wanted to know what the probability is of someone choosing Coke or Diet Coke, I can design an experiment and survey 200 people. Lets say 120 chose Diet Coke and 80 chose regular coke. The experimental probability of choosing Diet coke is .

**Theoretical Probability**: The
probability of an event, P(E) is the number of favorable outcomes divided by the
number of total outcomes.

For example: in the above problem the theoretical probability would be because you have a 1 in two chance of choosing Diet Coke (Diet coke would be the favorable outcome and there are two total possibilites)