6 7 Probability Probability refers to the likelihood

6. 7 Probability

Probability refers to the likelihood that an event will occur. Impossible Unlikely 50 -50 Chance 0% 50% Name some events that are: Impossible Unlikely 50 -50 chance Likely Certain 100%

Theoretical Probability • What should happen in theory. • Example: Flipping a coin, pulling M&M’s from a jar, choosing cards from a deck. The Probability of an Event “E” occurring: = the number of ways E can occur total number of possible outcomes

This picture shows the possible outcomes of rolling two dice. All 36 outcomes are equally likely.

A clothing store has the following inventory of shirts: Tee Polo Red 25 20 White 15 10 What is P(red tee)? What is P(blue or red)? Blue 10 30

Experimental (Historical) Probability • What should happen based on past events • Examples: – Predicting the next car that will pass through an intersection; – the chance of a basketball player making his next shot. – the chance of a teenager wrecking his car this year.

The Empirical Probability of an Event “E” occurring: = observed number of times E occurred total number of observed occurrences

So far this year, Kobe has made 300 shots out of 570 attempts. What is the probability that he will make his next shot?

Homework Probability Worksheet