1. Proportions Section 6.2

2. A proportion is a statement that two ratios or rates are equal. Solving Proportions If and are two ratios, then If and are two ratios, then is a proportion. is a proportion. a b c d a b c d = 2 Martin-Gay, Prealgebra, 5ed

3. Solving Proportions... A proportion contains four numbers. If any three numbers are known, the fourth number can be found by solving the proportion. To solve use cross products. a b c d a b c d = Multiply both sides by the LCD, bd Simplify ad = bc cross product ad bc These are called cross products. These are called cross products. 3 Martin-Gay, Prealgebra, 5ed

4. Determining Whether Proportions are True 4 Martin-Gay, Prealgebra, 5ed ? True proportion

5. Finding Unknown Numbers in Proportions 5 Martin-Gay, Prealgebra, 5ed Cross multiply. Simplify the left side. Divide both sides by 28. Check: (Rounded)