1. ALGEBRA READINESS LESSON 7-3 Warm Up Lesson 7-3 Warm-Up

2. ALGEBRA READINESS LESSON 7-3 Warm Up Lesson 7-3 Warm-Up

3. ALGEBRA READINESS “Percents and Proportions” (7-3) How do you find the percent of a number? Method 3: Proportion 55 1 So 22% of 250 is 55 #% Known (Part)x 22 Unknown (Whole)250 100 = Proportion. x 250 22 100 100 x = 250 22 Cross products are equal. 100x = 5500 Simplify. = Divide both sides by 100.. 100x 100 5500 100 1 1 x = 55 Simplify.

4. ALGEBRA READINESS Use a proportion to find 60% of 45. 100 n = 60 45 Write the cross products. 100n = 2,700 Simplify. n = 27Simplify. n 45 60 100 = Write a proportion. 100n 100 2,700 100 = Isolate the variable. Use the Division Property of Equality. Percents and Proportions LESSON 7-3 Additional Examples #% Known (Part)x 60 Unknown (Whole)45 100 27 1 1 1

5. ALGEBRA READINESS Suppose 11,550 students make up 14% of a city’s population. What is the population of the city? A diagram can help you understand the problem. 11,500 w 14 100 = Write a proportion. 11,550 100 = 14wWrite the cross products. =Isolate the variable. Use the Division Property of Equality. 1,155,000 14 14w 14 82,500 = w Simplify. Percents and Proportions LESSON 7-3 Additional Examples #% Known (Part)11,550 14 Unknown (Whole)w 100 82,500 1 1 1

6. ALGEBRA READINESS (continued) The population of the city is 82,500 people. Check for Reasonableness: 82,500 is about 80,000. Because 14% of 80,000 is 8,000 (10%) + 800 (1%) + 800 (1%) + 800 (1%) + 800 (1%) = 11,200, which is close to 11,155, the answer is reasonable. Percents and Proportions LESSON 7-3 Additional Examples

7. ALGEBRA READINESS 26 is what percent of 80? 26 is 32.5% of 80. 26 100 = 80pWrite the cross products. 2,600 = 80pSimplify. 32.5 = p Simplify. 80p 80 2,600 80 = Use the Division Property of Equality. to isolate the variable 26 80 p 100 = Write a proportion. A diagram can help you understand the problem. Percents and Proportions LESSON 7-3 Additional Examples #% Known (Part)26 p Unknown (Whole)80 100 1 1

8. ALGEBRA READINESS 1. Find 25% of 160. 2. 45 is 75% of what number? 3. Find what percent 68 is of 80. 40 85% 60 Percents and Proportions LESSON 7-3 Lesson Quiz