7.8 simple probability 1

Daily Homework Quiz For use after Lesson 4.3

Simplify

1.

1734

2. 1520

Daily Homework Quiz For use after Lesson 4.3

Simplify

1.

1734

ANSWER

12

2. 1520

ANSWER

34

Simple Probability

7.8

Calculators

You will need a scientific calculator for this unit.

Essential Questions

What are the differences between permutations and combinations?

What are the differences between odds and probability?

How is probability used to make predictions?

What are the differences between experimental and theoretical probabilities?

Vocabulary Probability of an event: the likelihood that the event

will occur.The probability of an event occurring is always

written as a number from 0 to 1.When it is impossible for an event to occur, the

probability is 0.When an event is certain to occur, the

probability is 1.

Vocabulary

Sample Space: is all possible outcomes for an activity or experiment.Rolling a die: 1, 2, 3, 4, 5, 6 (6 possible outcomes)Tossing a coin: Heads, Tails (2 possible outcomes)Drawing a card: 52 cards (52 possible outcomes)

Vocabulary Theoretical probability: what’s suppose to happen

P(event) = Number of favorable outcomes

Number of possible outcomes

Experimental probability: is based on the results of a sample or experiment. (what actually happened)

P(event) = Number of favorable outcomes

Total number of times the experiment was performed

Kari and Susie are playing a game with three colored markers- green, red and blue. On her next turn, if Susie chooses a marker at random and it is green, she wins the game.

What are the outcomes that could happen?green, red, blue

What is the probability of choosing a green marker?1/3, 0.3, 33 1/3%

Nicole found out that Jessica was born in May. What is the probability that she can guess the correct date of Jessica’s birthday on the first try?

How many outcomes are possible?31 days in May

What is the probability of the event?1/31

More Probability and other stuff

If you roll one die what is the probability that the number that shows is greater than 4?

If I roll one die the probability that the number that shows is greater than 4 is 2/6 which simplifies to 1/3.

The possibilities would be 1, 2, 3, 4, 5, 6. The only two numbers greater than 4 would be 5 and 6.

I have 3 pennies and 5 dimes in my pocket. If I pull out one coin what is the probability that I get a dime?

The probability that I get a dime is 5 chances out of eight.

5/8, 0.625, 62.5%

What is the probability that the spinner will land on . .

•Red• 2/5, 0.4, 40%

•Red or blue• 1, 1.0, 100%

• Green• 0, 0, 0%

• Not red• 3/5, 0.6, 60%

Red

Red

BlueBlue

Blue

EXAMPLE 2 Finding Experimental Probability

You roll a number cube 100 times. Your results are given in the table below.

Find the experimental probability of rolling a 6.

P(rolling a 6)= 18100

Number of favorable outcomesTotal number of rolls

= 0.18 = 18%

The experimental probability of rolling a 6 is 18% or 9/50.

ANSWER

EXAMPLE 2 Finding Experimental Probability

You roll a number cube 100 times. Your results are given in the table below.

Find the experimental probability of rolling a 1 or 2.

P(rolling a 1 or 2) = 32100

Number of favorable outcomesTotal number of rolls

= 0.32 = 32%

The experimental probability of rolling a 1 or 2 is 32% or 8/25.

ANSWER

17+15= 32

Explain the difference between experimental and theoretical probability.

Janet says that experimental probability can exceed 1. Is this true? If so, give an example.

HomeworkPage 383 #1-13, 20-23#20-23:

Y

R

B

Y

R

B

RG