9-1 Simple Events (pg ) D7: Compute probabilities of events

Probability – Chance of an event occurring Measured by…… P(event) = number of favorable outcomes total possible outcomes Example: P(tails) = 1 (tail) ( read probability of getting tails) 2 (outcomes)

Probability Continuum 0 ¼ =25% ½ =50% ¾ =75% 1=100% very unlikely unlikely likely very likely Impossible equal certain What is an example of an impossible event? What is an example of a certain event? What is an example of an unlikely event? What is an example of a very likely event?

Example: P(tails) & P(not tails) are… complementary events The probability of an event and its complement add up to 1 P(A) + P(not A) = 1 Another Example: P(tails) & P(not tails) = 1 Complementary Events (opposite events)

You try… There are 5 blue marbles, 3 red marbles and 2 yellow marbles in a bag. Find (in fraction and percent) P(Blue) P(not Blue) P(green) P(red or blue)

Homework Page #10-44 even only