1. Probability

2. Probability Terms:
Experiment: an activity in which results are observed.
Trial: each observation within an experiment.
Outcome: each result in an experiment.
Event: any set of one or more outcomes.
Sample space: the set of all possible outcomes of an experiment
EX: The sample space when rolling a die is 1, 2, 3, 4, 5, 6. An outcome would be rolling a 6. An event is what you’re finding the probability of…such as the probability of rolling a 1, 3, or 5.

3. Tomorrow will be Friday
Probability is a measure of how probable it is that an event will occur.
There will be a snow day tomorrow
You will have homework tonight
What other examples can you think of???
Pizza will be served for lunch today
The sky will darken tonight
Tomorrow will be Friday
P = 1
P = 0
P = 0.25
P = 0.5
P = 0.75
It is not very likely it’ll happen.
It might happen
There is a strong chance it’ll happen
It’ll definitely happen!!!
It’ll NEVER happen!!!

4. Experimental Probability
Data is collected through observations or experiments.
Each result from the experiment is called an event.
The probability of an event is equal to the number of times an event occurs divided by the total number of experiments.
P (event) =
Number of times an event occurs
Total number of experiments

5. Experimental Probability
P (event) =
Number of times an event occurs
Total number of experiments
Event = scoring a basket 2 1 1 3 1
Number of baskets scored
Number of shots taken

6. Theoretical Probability When you flip a coin there are
When all possible events or outcomes are equally likely to occur, the theoretical probability can be found without collecting data from an experiment.
Heads
A penny has two sides
When you flip a coin there are
two possible outcomes
or Tails
P (event) =
Number of favorable outcomes
Total number of possible outcomes
Heads
Heads or Tails 1 2 =
Tails
Heads or Tails 1 2 =

7. Flip a coin 50 times!!! Heads Tails
How many possible outcomes are there when flipping a coin? _________
What is the theoretical probability that you will get “heads “when flipping a coin? _________
Flip a coin 50 times!!!
Record your results below
Heads
Tails
What did you get for the experimental probability of getting heads? ________

8. If a die is rolled, how many possible outcomes are there?
Rolling a Die
If a die is rolled, how many possible outcomes are there? 6
What is the theoretical probability that you will throw a six?
What is the theoretical probability that you will throw a two?
What is the theoretical probability that you will throw a seven?
What is the theoretical probability that you will throw an even number? 1 6 1 6 6 3 6 1 2

9. Odds
Probability is the number of favorable outcomes over the total amount of outcomes. ODDS in favor are the number of favorable outcomes over the number of unfavorable or outcomes. ODDS against are the number of unfavorable outcomes over the number of favorable outcomes.
EX:
What are the odds in favor of drawing a 4 out of a deck of 52 cards?
4:48 = 1:12
What are the odds against drawing a 4 out of a deck of 52 cards?
48:4 = 12:1