Proportion Graphing Activity Monday, December 16, 2012

Problem of the Day The sum of four consecutive integers is 182. What are the four numbers? 44, 45, 46, and 47 Course Dimensional Analysis

Proportional???

Course Solving Equations Containing Percents Sloths may seem lazy, but their extremely slow movement helps to make them almost invisible to predators. Sloths sleep an average of 16.5 hours a day. To find out what percent of a 24-hour day 16.5 hours is, you can use a proportion or an equation.

Course Solving Equations Containing Percents Proportion Method Equation Method n 100 = Part Whole Part Whole What percent of 24 is 16.5? n · 24 = 100 · n = 1,650 n = n · 24 = 16.5 n = n = 68.75% Sloths spend about 69% of the day sleeping!

Solve. Additional Example 1A: Using Proportions to Solve Problems with Percents Course Solving Equations Containing Percents A. 25 is what percent of 40? n 100 = n · 40 = 100 · 25 40n = 2,500 40n 40 = 2, n = is 62.5% of 40. Write a proportion. Set the cross products equal. Multiply. Divide each side by 40 to isolate the variable.

Solve. Additional Example 1B: Using Proportions to Solve Problems with Percents Course Solving Equations Containing Percents B. 15 is 25% of what number? = 15 n n · 25 = 100 · 15 25n = 1,500 25n 25 = 1, n = is 25% of 60. Write a proportion. Set the cross products equal. Multiply. Divide each side by 25 to isolate the variable.

Solve. Try This: Example 1A Course Solving Equations Containing Percents A. 10 is what percent of 50? n 100 = n · 50 = 100 · 10 50n = 1,000 50n 50 = 1, n = is 20% of 50. Write a proportion. Set the cross products equal. Multiply. Divide each side by 40 to isolate the variable.

Solve. Try This: Example 1B Course Solving Equations Containing Percents B. 8 is 40% of what number? = 8n8n n · 40 = 100 · 8 40n = n 40 = n = 20 8 is 40% of 20. Write a proportion. Set the cross products equal. Multiply. Divide each side by 25 to isolate the variable.

Solve. Additional Example 2A: Using Equations to Solve Problems with Percents Course Solving Equations Containing Percents A. 35 is 28% of what number? 35 = 28% · n 35 = 0.28 · n = 0.28 · n = n 35 is 28% of 125. Write an equation. Write 28% as a decimal. Divide each side by 0.28 to isolate the variable.

Solve. Additional Example 2B: Using Equations to Solve Problems with Percents Course Solving Equations Containing Percents B. 18 is what percent of 9? 18 = n · = n · = n 200% = n 18 is 200% of 9. Write an equation. Divide each side by 9 to isolate the variable. Write the decimal as a percent.

Solve. Try This: Example 2A Course Solving Equations Containing Percents A. 36 is 24% of what number? 36 = 24% · n 36 = 0.24 · n 150 = n 36 is 24% of 150. Write an equation. Write 24% as a decimal. Divide each side by 0.24 to isolate the variable = 0.24 · n 0.24

Solve. Try This: Example 2B Course Solving Equations Containing Percents B. 36 is what percent of 6? 36 = n · = n · = n 600% = n 36 is 600% of 6. Write an equation. Divide each side by 6 to isolate the variable. Write the decimal as a percent.

Workers in Canada earn 10 vacation days, and workers in Finland earn 30 vacation days. What percent of the vacation days that workers in Canada earn do workers in Finland earn? Additional Example 3: Social Studies Application Course Solving Equations Containing Percents n · 10 = 30 n · = n = 3.0 Workers in Finland earn 300% of the number of vacation days that workers in Canada earn. Write an equation. Divide each side by 10 to isolate the variable. Write the decimal as a percent. Restate the question: What percent of 10 is 30? n = 300

Workers in Canada earn 10 vacation days, and workers in Britain earn 20 vacation days. What percent of the vacation days that workers in Canada earn do workers in Britain earn? Try This: Example 3 Course Solving Equations Containing Percents n · 10 = 20 n · = n = 2.0 Workers in Britain earn 200% of the number of vacation days that workers in Canada earn. Write an equation. Divide each side by 10 to isolate the variable. Write the decimal as a percent. Restate the question: What percent of 10 is 20? n = 200

Lesson Quiz is 42% of what number? is what percent of 292? % of what number is 84? is what percent of 1340? 5. An ad shows a DVD player on sale for 75% of its original price. If its original price was $242, what is the sale price? 25% 50 Insert Lesson Title Here 75 1% Course Solving Equations Containing Percents $181.50

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