1. Intro to Probability
Math 9

2. Probability – the likelihood or chance of an event occurring
Probability – the likelihood or chance of an event occurring. Probability can be expressed as a ratio fraction or percent.
Probability can be used to understand sports, games, behaviours and many other things.
Some professions that require the understanding of probability include nursing, medicine, business research, meteorology and insurance business.

3. Example 1: What is the probability of rolling a six with one die?
Possibilities are 1, 2, 3, 4, 5, 6.
𝑜𝑟 16.7%
Number of desired possibilities
Divided by the total possibilities

4. Example 2: What is the probability of rolling 2 sixes in a row
Die 1 = 1
Die 1 = 2
Die 1 = 3
Die 1 = 4
Die 1 = 5
Die 1 = 6 1 2
1 3 3 4 5
2 6
3 6

5. Example 2: What is the probability of rolling a 2 sixes in a row
Example 2: What is the probability of rolling a 2 sixes in a row? Instead of creating a table you can multiply the probability from the separate die to get the same answer. 1 6 ∗ 1 6 = 1 36

6. What is the probability of picking up a red queen in a deck with no jokers and then rolling a three? 2 52 ∗ 1 6 = = OR 0.64 %

7. Lebron has an 85% free throw percentage
Lebron has an 85% free throw percentage. If he were to take 520 free throws, how many would you predict he would make? 520 ∗ 0.85 = 442 Remember, probability is based on the likelihood something may happen it is not a certainty. Lebron may make more or less baskets than what we calculated.

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