1. Lesson 6-6: Testing for Proportionality Objective: We will learn ways to check whether two ratios are proportional. 1.One way is to rewrite the ratios in lowest terms and see if they are equal. Example: Decide if the ratios 4/12 and 8/24 are proportional. 4 = ÷ 4 = 1 ? 8 = ÷ 8 = 1 YES! 12 = ÷ 4 = 3 = 24 = ÷ 8 = 3

2. 2. Another way to check whether 2 ratios are proportional (or equal) is to see if the numerators or the denominators are related by multiplication. For Example: Decide if the ratios 6/9 and 24/36 are proportional. So you must ask yourself: 6 times what is 24? And does 9 times the same number give me 36? Let’s see…. 6 × ? = 24 9 × ? = 36 Think: 6 times 4 is 24; is 9 times 4 = 36?? If your answer is YES, then the proportions are equal. SO YOUR ANSWER IS YES!

3. TEXTBOOK PAGE 301 #’S 2-11. IN THIS HW YOU HAVE TO CHECK IF THE 2 PROPORTIONS ARE EQUAL AND ANSWER YES OR NO FOR EACH PROBLEM. REMEMBER TO SHOW YOUR WORK. HOMEWORK: