1. PROPORTIONS Section 1.6 We will use proportions to analyze proportional relationships and to solve real-life problems.

2. WHAT THE HECK IS A PROPORTION? A relationship between two ratios that are _______________. WHAT DOES A PROPORTION LOOK LIKE? 4 = b 6 3

3. WHAT IS A PROPORTION USED FOR? To find an ______ value in one ratio when given another ______ ratio. HOW DO WE SOLVE A PROPORTION? We find the ________, where we multiply the numerator of one ratio with the denominator of the other ratio.

4. *Step 1: Find the cross products *Step 2: Compare the cross products 2 = 10 3 15 LET’S PRACTICE DETERMINING IF TWO RATIOS ARE PROPORTIONAL 30 YES!

5. *Step 1: Find the cross products *Step 2: Compare the cross products 15 = 9 12 6 LET’S PRACTICE DETERMINING IF TWO RATIOS ARE PROPORTIONAL NO!

6. Is the following ratio proportional? 4 = 16 5 20 WHITE BOARD TIME!!

7. Is the following ratio proportional? 6 = 18 10 30 WHITE BOARD TIME!!

8. Is the following ratio proportional? 1 = 4 8 24 WHITE BOARD TIME!! 24 32

9. Try on your Own 1. The ratio of 7 th grade students to 8 th grade students in a soccer league is 17:23. If there are 200 students in all, how many are in the 7 th grade?

10. Try on your Own 2. After 2 hours, the air temperature had risen 8 degrees. Write and solve a proportion to find the amount of time it will take at this rate for the temperature to rise and additional 13 degrees.

11. Use Unit Rate You can also use the unit rate to write an equation expressing the relationship between two proportional quantities. Example: Olivia bought 6 containers of yogurt for $7.68. Write an equation relating the cost c to the number of yogurts y. How much would Olivia pay for 10 yogurts at this same rate?

12. Practice Solve each proportion: 1. k = 32 7 56 2. 3.2 = n 9 36 3.Evarado paid $1.12 for a dozen eggs at his local grocery store. Determine the cost of 3 eggs.

13. Essential Question How do you solve a proportion? ________________________________________________ ________________________________________________ ________________________________________________ ________________________________________________