Lesson 9-1 Pages 370-373

Simple Events

Lesson Check Ch 8

What you will learn!

How to find the probability of simple events.

OutcomeOutcomeSimple eventSimple eventProbabilityProbabilityRandomRandomComplementary eventComplementary event

What you really need to know!

The probability of an event is a ratio that compares the number of favorable outcomes to the number of possible outcomes. Outcomes occur at random if each outcome occurs by chance.

What you really need to know!

Two events that are the only ones that can possibly happen are complementary events. The sum of the probabilities of complementary events is 1.

What you really need to know!

outcomes possible ofnumber

outcomes favorable ofnumber P(event)

possible

favorableP(event)

Example 1:

If the spinner shown below is spun once, what is the probability of its landing on an odd number?

possible

favorableP(event)

2

1

4

2P(odd)

Example 2:

A game requires spinning the spinner shown below twice. If the sum of the two spins is 6 or greater, the player wins. What is the probability of winning the game?

1, 11, 1 2, 12, 1 3, 13, 1 4, 14, 1

1, 21, 2 2, 22, 2 3, 23, 2 4, 24, 2

1, 31, 3 2, 32, 3 3, 33, 3 4, 34, 3

1, 41, 4 2, 42, 4 3, 43, 4 4, 44, 4

1, 11, 1 2, 12, 1 3, 13, 1 4, 14, 1

1, 21, 2 2, 22, 2 3, 23, 2 4, 24, 2

1, 31, 3 2, 32, 3 3, 33, 3 4, 34, 3

1, 41, 4 2, 42, 4 3, 43, 4 4, 44, 4

1, 11, 1 2, 12, 1 3, 13, 1 4, 14, 11, 21, 2 2, 22, 2 3, 23, 2 4, 24, 21, 31, 3 2, 32, 3 3, 33, 3 4, 34, 31, 41, 4 2, 42, 4 3, 43, 4 4, 44, 4

8

3

16

6

possible

favorableP(winning)

Example 3:

A game requires spinning the spinner shown below twice. If the sum of the two spins is 6 or greater, the player wins. What is the probability of not winning the game?

1, 11, 1 2, 12, 1 3, 13, 1 4, 14, 1

1, 21, 2 2, 22, 2 3, 23, 2 4, 24, 2

1, 31, 3 2, 32, 3 3, 33, 3 4, 34, 3

1, 41, 4 2, 42, 4 3, 43, 4 4, 44, 4

1, 11, 1 2, 12, 1 3, 13, 1 4, 14, 1

1, 21, 2 2, 22, 2 3, 23, 2 4, 24, 2

1, 31, 3 2, 32, 3 3, 33, 3 4, 34, 3

1, 41, 4 2, 42, 4 3, 43, 4 4, 44, 4

1, 11, 1 2, 12, 1 3, 13, 1 4, 14, 11, 21, 2 2, 22, 2 3, 23, 2 4, 24, 21, 31, 3 2, 32, 3 3, 33, 3 4, 34, 31, 41, 4 2, 42, 4 3, 43, 4 4, 44, 4

8

5

16

10

possible

favorableP(losing)

Example 3: Method 2

1 A)P(not P(A)

1 P(not win)8

3

P(not win)8

31

P(not win)8

3

8

8

P(not win)8

5

Page 372

Guided Practice

#’s 4-9

Pages 370-371 with someone at home and study

examples!

Read:

Homework: Page 372-373

#’s 10-28

#’s 31-44

Lesson Check 9-1

50 Total Kids

Link to Math Review Practice

Page

584

Lesson 9-1Lesson Check 9-1

Lesson Check 9-1