1. Vocabulary
prediction

2. A prediction is something you can reasonably expect to happen in the future. Weather forecasters use several different methods of forecasting to make predictions about the weather.
One way to make a prediction is to use probability.

3. Additional Example 1: Using Experimental Probability to Make Predictions
Lawrence finds that his experimental probability of getting a hit is 40%. Out of 350 at-bats, how many times can he expect to get a hit?
Method 2: Set up a proportion.

4. Check It Out: Example 1
Marty finds the experimental probability of him making a field goal to be 74%. Out of 150 field goal attempts, how many times can he expect to make a field goal?

5. Additional Example 2: Using Theoretical Probability to Make Predictions
A spinner has eight sections of equal size. Three sections are labeled 1, two are labeled 2, and the others are labeled 3, 4, and 5. In 50 spins, how often can you expect to spin a 1?

6. Round to a whole number if it makes sense in the given situation.
Helpful Hint

7. Check It Out: Example 2
Rhonda rolls a number cube 330 times. How many times can she expect to roll a 5?

8. Additional Example 3: Problem Solving Application
The Singh family is planning a 7-day tropical vacation during July or August. The island destination they have chosen averages 21 rainy days during this 62-day period. If the Singhs would like to avoid rain on at least 5 days of their vacation, should they go to this spot or choose another?

9. Understand the Problem
Additional Example 3 Continued 1
Understand the Problem
The answer will be whether the Singh family
should go to the island.
List the important information:
• The island destination averages 21
rainy days out of 62 days.
• The Singhs want to avoid rain on at least 5
days of their vacation.

10. Additional Example 3 Continued2
Make a Plan
On average 21 out of the 62 days it is rainy. After
finding out the number of rainy days there should
be forecast, subtract to find the number of not
rainy days.

11. Additional Example 3 Continued
Solve 3

12. Check It Out: Example 3
The Berry family is planning a 12-day vacation to a beach. The beach they have chosen averages 45 rainy days during this 109-day period. If the Berrys would like to have no rain on at least 7 days of their vacation, should they go to this spot or choose another?

13. Lesson Quiz: Part I
1. The experimental probability of Maura shooting a goal in field hockey is 12%. Out of 300 shots, how many can Maura predict will be goals?
2. If Scott flips two quarters 25 times, how many times can he expect to flip two heads?

14. Lesson Quiz: Part II
3. The Aurelio family is planning a 12-day skiing trip during December or january. The region they have chosen gets the right conditions for skiing 46 days during the 62-day period. The Aurelios would like to spend at least 8 days skiing. Will their destination be a good choice?

15. Lesson Quiz for Student Response Systems
1. Katia finds the probabilty that the traffic light is red when she reaches an intersection is 45%. In one month, she goes through the intersection 65 times. How many times can she expect the light to be red when she reaches the intersection?
A. 22
B. 26
C. 30
D. 45 15 15 15 15

16. Lesson Quiz for Student Response Systems
2. If you roll a number cube 12 times, about how many times do you expect to roll a number less than five?
A. 6
B. 8
C. 10
D. 12 16 16 16 16