1. PERCENT PROPORTIONS Using Proportions 4-1

2. Vocabulary Review Ratio: The comparison of two numbers (written in Algebra as a fraction) Proportion: When two ratios are equal to each other Cross Product(s): When we cross multiply/compare diagonally, the special relationship between two ratios in a proportion

3. Percent Proportions Proportions can be used to solve missing percentages of a number… “is #” = given/missing % “of #” 100%

4. Percent Proportions Ex. Find 30% of 24. Is # = Of # = Given/missing % = Write out proportion… x = 30% 24 100% *Round answer to nearest tenth of percent! Ex. What percent is 20 of 210? Is # = Of # = Given/missing % = Write out proportion… = 100% *Round answer to nearest tenth of percent! We use the same steps to solve… 1) Cross multiply 2) Cross multiply 3) Divide to solve

5. Percent Proportions Ex. What is 33 1/3 % of 150? x = 33.3% 150 100% Ex. 5 is 80% of what number? 5 = 80% x 100%

6. Practice A) 6% of what number is 2.46 B) What percent of 72 is 27? C) Find 72% of 310.

7. Homework p. 161 #9-20 all (Calculator okay!) Show set up/process/work