1. SETTING UP A PROPORTION SPI 6.1.1 Predictions & Conjectures SPI 6.2.6 Rates & Percents

2. What is a proportion?  A proportion is 2 equivalent ratios. Example: 6 = 3 2010 What is a ratio?  A ratio is a comparison of two numbers by division. Example: 6 black socks to a total of 20 socks

3. Using Proportions to solve Predictions  Out of the 32 students in a health class, 24 prefer using gel toothpaste. Based on these results, how many of 500 students in the school can be expected to prefer using gel toothpaste? Ratio:prefer gel toothpaste total students in class Answer: 375 students out of 500 prefer gel toothpaste PART TOTAL

4. Using Proportions to solve Ratios  At West Boulevard Middle School, the teacher to student ratio is 3 to 78. If there are 468 students enrolled at the school, how many teachers are there at the school? Answer: 18 teachers to 468 students

5. Proportions to solve Percent of a Number  The Mooney High School football team won 75% of their football games. If they played 12 games, how many did they win? Answer: won 9 games out of 12 total games

6. Setting Up a Proportion  Suppose you buy 2 CDs for $21.99. How many CDs can you buy for $65.97? Answer: 6 CDs for $65.97

7. Using Proportions to solve Discounts  A skateboard is on sale for 85% of the regular price. If it is regularly priced at $40, how much is the sale price?  How much is the discount? Answer: $34 sale price Answer: $6 discount

8. Using a Proportion to solve Unit Rate  If you work 22 hours a week and earn $139.70, how much money do you earn per hour? Answer: You earn $6.35 every hour

9. Proportions to solve Percent of a Number  Chad and Alisa donated 30% of their book collection to a local children’s hospital. If they had 180 books, how many did they donate to the hospital? Answer: 54 children's books out of 180 books total

10. Proportions to solve Probability Lorenzo asked every tenth student who walked into school to name their favorite pizza topping. 1) What is the probability that a student will prefer pepperoni pizza? 2) There are 384 students at the school Lorenzo attends. Predict how many students prefer pepperoni pizzas. Favorite Pizza Topping ToppingStudents Pepperoni18 Cheese9 Sausage3 Mushroom2 Answer: 18/32 Answer: 216 prefer pepperoni pizzas

11. Proportions to solve Predictions  Use the results shown to predict the number of people out of 300 that would prefer vanilla ice cream? Favorite Ice Cream FlavorAmount Vanilla9 Chocolate8 Strawberry3 Answer: 135 prefer vanilla ice cream

12. Using Proportions to solve Discounts  The regular price of a pair of sneakers is $40. The sale price is 17% off the regular price. What is the sale price? Answer: The sales price of the sneakers is $33.20