1. Bell Quiz

2. Objectives Calculate probabilities of simple events.
Express probabilities as fractions, decimals, or percents.

3. Sample Space
A sample space is the set of all possible outcomes of an event.
For example, a toss of a fair coin has two equally like outcomes.
Heads
Tails
(This is the sample space.)

4. Simple Event A simple event is an event having only one outcome.
For example, rolling a 5 on a number cube is a simple event.

5. Example 1 Identifying Sample Space
A number cube labeled 1 – 6 is rolled. List the outcomes for each event.
A number less than or equal to 3
An odd number
A number greater than 4

6. Lesson Practice
A number cube labeled 1 – 6 is rolled. List the outcomes for each event.
A number less than or equal to 4
An even number
A number greater than 2

7. Theoretical Probability
The theoretical probability of an out come is found by analyzing a situation in which all outcomes are equally likely.
Then finding the ratio of favorable outcomes to all possible outcomes.
For example, the probability of tossing a coin and it landing on heads is ½ or 0.5 or 50%.

8. Theoretical Probability
Theoretical Probability can be determined using the following formula:
number of favorable outcomes
P(event) =
total number of outcomes

9. Complement of an Event
A complement of an event is a set of all outcomes of an experiment that are not in a given event.
For example, if heads is the desired event when tossing a coin, tails is the complement of the event.
The sum of an event and its complement equals 1
P(event) + P(not event) = 1
P(not event) = 1 – P(event)

10. Example 2 Calculating Theoretical Probability
There are 4 green, 3 blue, and 3 red marbles in a bag. Give each answer as a decimal and as a percent.
What is the probability of randomly choosing a red marble?
What is the probability of randomly choosing a marble that is not green?

11. Lesson Practice There are 4 green, 3 blue, and 3 red marbles in a bag.
What is the probability of randomly choosing a blue marble?
What is the probability of randomly choosing a marble that is not red?

12. Example 3 Calculating Chance
In a bucket there are 10 balls numbered as follows: 1, 1, 2, 3, 4, 4, 4, 5, 6, and 6. A single ball is randomly chosen from the bucket. What is the probability of drawing a ball with a number greater than 4? Is there a greater chance of drawing a number greater than 4 or drawing a 1?

13. Lesson Practice
Suppose there are 8 balls in a bucket numbered as follows: 1, 2, 3, 5, 5, 6, 7, and 7. A single ball is randomly chosen from the bucket. What is the probability of drawing a ball with a number less than 6? Do you have a greater chance of drawing a 7 or a 6?

14. Example 4 Application
A 52-card deck has 4 kings. What is the probability of randomly drawing a king out of the deck?