Solving Proportions

Solving Proportions

by Scott Donnelly

​Proportions

​Parts of a Ratio

​Determining Proportions

​Example

​Example

Multiple Choice

Are the 2 ratios proportions?

$$\frac{4}{7}=\frac{12}{21}$$  

• Yes

• No

Multiple Choice

Are the 2 ratios proportions?

$$\frac{5}{8}=\frac{10}{24}$$  

• Yes

• No

Fill in the Blank

Are two proportions equal?

$$\frac{2}{7}=\frac{10}{28}$$  

​Finding Missing Value

​To find a missing value you follow a 2 step approach

1. ​Cross multiply

2. ​Divide.

​Example

​Example

Multiple Choice

Find missing value

$$\frac{3}{5}=\frac{24}{x}$$  

• $$x=16$$  

• $$x=120$$  

• $$x=40$$  

Fill in the Blank

Find the missing value

$$\frac{5}{x}=\frac{25}{40}$$  

​Solving Proportion