Ratio and Proportion....................

RATIO & PROPORTION

1. PROPORTION

2. PROPORTION A statement that two ratios are equal is called a proportion. If and are two equal ratios, then:   is called a proportion .  

3. PROPORTION Each of the four numbers in a proportion is called a term of the proportion. That is: first term   From ,   second term   third term   fourth term   The first and fourth terms are called the extremes . The second and third terms are called the means .

4. FUNDAMENTAL PROPERTY OF PROPORTION In any proportion, the product of the means is equal to the product of the extremes . That is, the cross products of the terms are equal . In symbols, If  

5. PROPORTION Example. Verify that using the Fundamental Property of Proportions.  

6. PROPORTION Example. Verify that using the Fundamental Property of Proportions.   Solution: Equating the cross products of the terms gives,  

7. We also use the Fundamental Property of Proportions to find the missing term in a proportion. Example: We set cross products equal:   PROPORTION

8. Example. Use the Fundamental Property of Proportions to find the missing term in a proportion. Solve for n: We set cross products equal:   PROPORTION

9. Example 1. It takes Andy 30 minutes to burn 200 calories in a treadmill. How long will it take for Andy to burn 400 calories?    

10. Example 2. If Trina works 20 hours, she earns Php 600. How much does she earn if she works 30 hours?