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## Bell work

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**Bell work**Solve each proportion: • 5 = x 6 12 • a = 2 184 • 2 = 5 6 t 10 9 15**Ratio and Proportion**A recipe that serves 4 people uses 5 potatoes. How many potatoes are needed to serve 28 people? # 1 Let x be the number of potatoes required to serve 28 people. # 2 Since the recipe is the same, we have two equivalent ratios: # of people: # of potatoes: # 3 Cross multiply 4x = 5 (28) 4x = 140 # 4 Divide by 4 to find x x=35 potatoes**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**Your class has raised80%of its goal of$8000for a trip to**Washington, D.C. How much money has your class raised for the trip? = 6400 ANSWER Your class has raised$6400for the trip to Washington, D.C. Finding a Part of a Base Write percent equation. Substitute80for pand8000for of. Solve using mental math or cross products**ANSWER**6%of the seedlings did not bloom. Finding a Percent A service club is planting seedlings as part of a project. Out of 250newly planted seedlings, 15did not bloom. What percent of the seedlings did not bloom? Write a percent proportion. Substitute 15 for isand 250for of. Solve using cross products 6%**Student Council**Marc received 273, or 35%, of the votes in the student council election. How many students voted in the election? ANSWER 780 students voted in the election. Finding a Base Write percent equation. Substitute 273 for isand 35 for %. 780 = of Solve using cross products**Find the Percent**72 is what percent of 160? Find the cross products: 72100 = 160P Simplify: 7200=160P Divide: 7200 = 160P 160 160 Solve: 45 = P So 72 is 45% of 160**Find the Base**• 27 is 90% of what number? Cross Products: 27100 = b90 Simplify: 2700 = 90b Divide: 2700 = 90b 90 90 Solve: 30= b So, 27 is 90% of 30**Apply the Percent Proportion**• If 12 of the 75 animals in a pet store are parakeets, what percent are parakeets? Cross Products: 12100 = 75P Simplify: 1200 = 75P Divide: 1200 = 75P 75 75 Solve: 16 = P So, 16% of the animals are Parakeets**Apply the Percent Proportion**• Of the fish in an aquarium, 26% are angelfish. If the aquarium contains 50 fish, how many are angelfish? a100 = 5026 100a = 1300 a = 13 So, 13 fish are angelfish**Your Turn! Use the percent proportion to solve each**problem. 17 = P 100 P = 20 20% 17 is what percent of 85? 36 is 72% of what number? What is 84% of 150? 36 = 72 b 100 b = 50 a = 84 100 a = 126