Probability in Society Chapter 9 of Grade 9 Math

Theoretical Probability: the mathematical outcomes from a concrete event (represented by a fraction or percentage) Known whole: Ex. Rolling dice (only 6 sides, doesn’t change), drawing cards (52 cards, doesn’t change)

Experimental Probability Experimental Probability: the probability of an event calculated from experimental results (never exact or for sure, changes over time) Ex. Shooting a basketball, colour of cars in lot

Subjective Influences on Probability Subjective Judgement: the decisions you make around possible outcomes Ex. Your gut feelings: I feel like the next roll of the die will show a 4, I always call heads, my lucky number is 16.

Indicate whether each decision is based on theoretical probability or experimental probability.

The last two times Matt won a prize at a coffee shop, he ordered a medium hot chocolate. Matt never won when he ordered a large hot chocolate, so today he orders a medium hot chocolate

Instead of buying her own lottery ticket, Jen pools her money with the people at work to buy more tickets and increase her chances of winning.

Selena boards the last car of a train because, in the past, the last car always had available seats.

Tyler will not travel by airplane even though experts say it is safer to fly than drive.

What assumptions is each person making? Based on past math quizzes, Joan says she has a 90% chance of getting a perfect score on her next math quiz. Six times out of ten, Matt gets stuck in traffic when he leaves work. So, he calculates that his chances for getting stuck in traffic today after work are 60%

Assignment Come up with 5 events showing either theoretical probability or experimental probability For each event explain if it is theoretical or experimental and what subjective judgments are present