PROBABILITY What are the chances?

EXPERIMENTAL PROBABILITY The ratio of the number of times an event occurs to the total number of trials or times the activity is performed. The number of ways that an event can occur, divided by the total number of outcomes. The probability of events that come from a sample space of known likely outcomes.

15, 5 15, 5 n/a, n/a 6, 6

Measures of Central Tendency Mean (average): Add the set of data and then divide by the number of the data set Mode (most): the data that is listed the most times Median (middle): the mean of the middle numbers Range: the difference between the greatest and least

Student Name Red Card Black Card

Likely or Unlikely? Definitely going to occur What is the chance of pulling out a purple marble without looking? P(purple) = Blue? P(blue) = Might occur Red? P(red) = Orange? P(orange) = Green? P(green) = P(event) = # of ways it can happen total number of outcomes Definitely NOT going to occur

UNLIKELY AS LIKELY AS NOT LIKELY

Experimental Probability 68 67 65 75 45 58 51 49 74 80 78 77 63 54 79 84 70 72 71 56 53 40% The ratio of the number of times an event occurs to the total number of trials or times the activity is performed. 6 out of 15 days had a temperature greater than 75° 100% Everyday had a temperature less than 75° # of times the event occurs 0% There were no days that had a temperature greater than 100° total # of trials

Independent Events P(A and B) = P(A) • P (B) Two or more events that do not affect each other

Two or more simple events Ex: tossing 2 dice flipping 3 coins 1st 2nd 3rd Tree Diagram Outcome   52 cards in a deck P ( , , ) Draw 3 cards without replacing P(A and B) = P(A) • P(B/A) When the outcome of one event, effects the outcome of another. Ex: choosing a marble from a bag and NOT replacing it before choosing another. P(A ) means Probability of Event A P(B/A) means Event B given Event A

Draw a tree diagram of rolling 2 number cubes. P(both number cubes are even) 1st cube 2nd cube Outcomes