Intro to Probability

Sample Space Sample space is the list of all possible outcomes. With a 6 sided die, Flip of a coin, Notice that we will us S to represent the full sample space.

Sample Space Sample space can come in different forms, depending on the style of the problem. Rolling 2 six-sided dice can have a sample space of

Sample Space Or…

Event If a sample space is a set of outcomes, then an event is a subset. A subset of rolling a six-sided die would be the even numbers. Or odd numbers. Notice that we will use different letters for different events (and never S).

Probability Models Which brings us to how to represent events. There are several ways that we will explore throughout the unit on probability, but some of the most basics are: Tree Diagrams Venn Diagrams Listing out S.

Tree Diagram Is useful in allowing us to see discrete (countable) outcomes. This also allows us to quickly compute probabilities.

Venn Diagram A Venn diagram allows us to consider continuous probabilities, as well as events that are not disjoint.

Remember… If you can draw it, do. Probability can be a scary and confusing place, filled with things we think are true, but instead are false. What you think you see and what you think you know about probabilities should be based on facts, not conjecture (unless we have nothing else to go on).