Probability of Simple Events

Impossible Certain 0 1 Even chance 1212 UnlikelyLikely Probabilities never have values less than 0 or more than 1 (remember 100 % is the same as 1 whole). Roll a 7 on a number cube Win the lottery Roll a 3 on a number cube Receive a text message Sun rise 25% 50% 75%

Probability written P(event) is a number from 0 (or 0%) to 1 (or 100%) A probability of 0 means the event is impossible, or can never happen. A probability of 1 means the event is certain, or has to happen. The probabilities of all the outcomes in the sample space add up to 1. equally likely same probability

An experiment consists of spinning this spinner once. Find the probability of each event. P(4) = The spinner is fair, so all 5 outcomes are equally likely: 1, 2, 3, 4, and How many fours How many outcomes P(even number) = = 2 5 P(odd number) 3.= P(3 or 2) 2 5 =

What is the probability of rolling a fair number cube? P(greater than 4)= 2 6 __ P(less than 4)= P(prime number)= 6 3 = 2 1 = 1 3 __ 6 3 = P( not a factor of 6) = 2 6 __ = 1 3 = 6 3 = 2 1 P( not even) If you roll a die 500 times how many times do you expect tails? 250

An experiment consists of spinning this spinner once. Find the probability of each event. P( not 4) = 4 5 P(not prime) = 2 5 P(not a multiple of 2 ) 12.= P(not yellow or red) 3 5

When you combine all the ways that an event can NOT happen, you have the complement of the event. The event plus it’s complement equal 1.

Essential Question Explain the relationship between the probability of an event and it’s complement.

Probability of Simple Events Date ______________________

Impossible Certain 0 1 Even chance 1212 UnlikelyLikely Probabilities never have values less than __ or more than __ (remember 100 % is the same as 1 whole). 25% 50% 75%

Probability written is a number from to A probability of means the event is __________, or can A probability of means the event is _______, or The probabilities of ____ the outcomes in the sample space add up to __________________ same probability

An experiment consists of spinning this spinner once. Find the probability of each event. The spinner is fair, so all 5 outcomes are equally likely: = 3. 4.

What is the probability of rolling a fair number cube? P(greater than 4)= P(less than 4)= P(prime number)= P( not a factor of 6) P( not even) If you roll a die 500 times how many times do you expect tails?

An experiment consists of spinning this spinner once. Find the probability of each event. P( not 4) P(not prime) P(not a multiple of 2 ) P(not yellow or red)

When you combine all the ways that an event can ____ happen, you have the _____________ of the event. The event _____ it’s complement equal __.

Essential Question Explain the relationship between the probability of an event and it’s complement.