2. Bell work Solve each proportion: 1.5 =x 612 2.a = 2 184 3.2 =5 6t 10 9 15

3. Proportions Day 2

4. Ratio and Proportion Let x be the number of potatoes required to serve 28 people. Cross Products 4x = 5 (28) 4x = 140 A recipe that serves 4 people uses 5 potatoes. How many potatoes are needed to serve 28 people? Since the recipe is the same, we have two equivalent ratios: # of people: # of potatoes: # 1 # 2 # 3 # 4 Divide by 4 to find x x=35 potatoes

5. Easy way to remember is = part of the whole (sometimes called part of base) of = total (sometimes called the base) % always goes over 100 since 100% = one whole

6. Types of Percent Problems TypeExampleProportion Find the % 3 is what percent of 4? 3 = P 4 100 Find the partWhat number is 75% of 4? is = 75 4 100 Find the base3 is 75% of what number 3 = 75 of 100

7. Finding a Part of a Base Your class has raised 80% of its goal of $8000 for a trip to Washington, D.C. How much money has your class raised for the trip? = 6400 Substitute 80 for p and 8000 for of. Solve using mental math or cross products ANSWER Your class has raised $6400 for the trip to Washington, D.C. Write percent equation.

8. Finding a Percent A service club is planting seedlings as part of a project. Out of 250 newly planted seedlings, 15 did not bloom. What percent of the seedlings did not bloom? Write a percent proportion. Substitute 15 for is and 250 for of. 6% ANSWER 6% of the seedlings did not bloom. Solve using cross products

9. Finding a Base Marc received 273, or 35%, of the votes in the student council election. How many students voted in the election? Student Council Write percent equation. Substitute 273 for is and 35 for %. 780 = of 780 students voted in the election. ANSWER Solve using cross products

10. Find the Percent 72 is what percent of 160? Find the cross products: 72  100 = 160  P Simplify: 7200=160P Divide: 7200 = 160P 160 160 Solve: 45 = P So 72 is 45% of 160

11. Find the Base 27 is 90% of what number? Cross Products: 27  100 = b  90 Simplify: 2700 = 90b Divide: 2700 = 90b 90 90 Solve: 30= b So, 27 is 90% of 30

12. Apply the Percent Proportion If 12 of the 75 animals in a pet store are parakeets, what percent are parakeets? Cross Products: 12  100 = 75  P Simplify: 1200 = 75P Divide: 1200 = 75P 75 75 Solve: 16 = P So, 16% of the animals are Parakeets

13. Apply the Percent Proportion Of the fish in an aquarium, 26% are angelfish. If the aquarium contains 50 fish, how many are angelfish? a  100 = 50  26 100a = 1300 a = 13 So, 13 fish are angelfish

14. Your Turn! Use the percent proportion to solve each problem. 17 is what percent of 85? 36 is 72% of what number? What is 84% of 150? 17 = P 85 100 P = 20 20% 36 = 72 b 100 b = 50 a = 84 150 100 a = 126

15. Practice: