Over Lesson 13–5

A. A

B. B

C. C

D. D

How many countries won between 1 and 10 medals?A. 18 C. 12B. 16 D. 10

How many countries won medals in the 1998 Winter Olympics?A. 32 B. 28C. 24 D. 10Which country won the greatest number of medals?

A. USA B. ChinaC. Canada D. cannot be

determined

You have already simplified ratios. (Lesson 6–1)

• Find the probability of simple events.

• Predict the actions of a larger group.

• outcomes

• simple event

• probability

• sample space

• random

• theoretical probability

• experimental probability

Possible result of a probability experiment

One outcome or a collection of outcomes.

The ratio of the number of ways a certain event can occur to the total number of possible outcomes

The set of all possible outcomes

Outcomes occur at random if each outcome is equally likely to occur (it is not fixed or has been manipulated)

What should occur in a probability experiment

What actually occurs in a probability experiment

Find Probability

Suppose a number cube is rolled. What is the probability of rolling a 4 or a 5?

There are 2 numbers on the number cube that are a 4 or a 5: 4 and 5.

There are 6 possible outcomes: 1, 2, 3, 4, 5, and 6.

Answer:

A. A

B. B

C. C

D. D

Suppose a number cube is rolled. What is the probability of rolling a number that is divisible by 3?

A. AnsA

B. AnsB

C. AnsC

D. AnsD

Find Probability

Suppose that two number cubes are rolled. Find the probability of rolling two identical numbers.

Make a table showing the sample space when rolling two number cubes.

Find Probability

There are 6 outcomes in which the two numbers are identical.

Answer:

A. A

B. B

C. C

D. D

Suppose that two number cubes are rolled. Find the probability of rolling two numbers whose sum is 8.

A.

B.

C.

D.

Find Experimental Probability

A coin was tossed 40 times and heads came up 18 times. Find the experimental probability of getting tails for this experiment. Then compare the experimental probability with the theoretical probability.

Find Experimental Probability

Answer: So, tossing tails in the experiment occurred more often than expected.

A. A

B. B

C. C

D. D

BASKETBALL Brian is shooting baskets with a basketball. He makes 13 shots and misses 9 shots. Determine the experimental probability of Brian making a shot.

A.

B.

C.

D.

Make a Prediction

SPORTS Miss Newman surveyed her class to see which sports they preferred watching. 44% preferred football, 28% basketball, 20% soccer, and 8% tennis. Out of 560 students in the entire school, how many would you expect to say they prefer watching basketball?

Understand You know that 28% prefer basketball. You need to find how many students out of 560 prefer basketball.

Plan Use the percent proportion to find 28% of 560.

Make a Prediction

part

wholepercent

Solve The percent is 28% and 560 is the whole. Let a represent the part.

Make a Prediction

Answer: You can expect about 157 students to say they prefer watching basketball.

Check Estimate: 28% is about 25%.25% of 600 is 150.So, 157 is reasonable.

A. A

B. B

C. C

D. D

A. about 6

B. 29

C. about 131

D. 144

COLORS The students in an art class were surveyed about their favorite color. 32% preferred blue, 29% preferred red, 23% preferred yellow, and 16% preferred green. Out of 450 students in the entire school, how many would you expect to say they prefer red?