Proportional Reasoning Section 2.3
Objectives: To solve problems using proportional reasoning. Use more than one method to solve proportional reasoning problems.
What Is A Proportion? Proportions are two ratios set equal to each other Example:
How Do You Know If A Proportion Is True? The cross-products of the ratios must be equal. Ex. Cross-Product… 4 x 10 = 40 and 5 x 8 = 40 It is a proportion!
Proportions & Variables Proportions may contain a variable. Example:
Solving Proportions That Contain Variables To solve for the variable you… CROSS MULTIPLY Step 1 Step 2 Step 3 Step 4 Step 5
Your Turn… Solve the following proportion:
Word Problems Using Proportions There is a ratio of 8 boys to 12 girls in a classroom. How many girls would there be if there were 12 boys in the classroom?
Homework 2.3 Proportions Worksheet