PLEASE PASS OUT YOUR ADVISORY FOLDERS! PROBABILITY What do you think the chances are…?

Probability…what is it?  Probability is the chance of an event occurring.  Its value ranges from 0 to 1.  0 means – not going to happen  1 means – always will happen  We find probability by measuring what we want to happen and putting it over the total outcomes that can happen

Example  A number cube, which is how dice is referred to as on the PSSA, is rolled. What is the probability we roll an odd number?  How many odd numbers are on a number cube?  How many total numbers (outcomes) are on a number cube? P(odd) = We can reduce this fraction P(odd) =

You try one  A bag of marbles contains 8 red, 5 blue, 1 black, and 2 green marbles. What is the probability of selecting a green marble? A) B) C) D)

What if two or more things need to happen?  Find the probability of each individual event.  If they need to happen together, find the product of the events.  Formula: P(event #1) P(event #2) = P(both events)

Example  Find the probability of flipping a coin and getting heads while rolling a number greater than 4 on a number cube.  P(heads) =  P(greater than 4) =  P(heads and greater than 4) =

You try one  Find the probability of spinning a red on the spinner and rolling an even number? A) B) C) D)