Introduction to Proportional Relationships

The ratio of girls to boys at basketball practice is 2:3. If there are 12 girls at practice then how many boys are there?

• 15

• 18

• 20

• 21

• y = 1/5x

• y = 5x

• y = 1/2x

What is the constant of proportionality? Use the format k = 4.

Is the graph proportional?

• Yes

• No

Write an equation for the relationship between x and y. Use format y = kx.

Select all graphs that represent a proportional relationship.

• 
• 

What is the constant of proportionality? Use the format k = 2.

Write the equation of the graph. Use the format y = kx.

Newtown middle school spends 11 dollars on every yearbook it buys. Is the amount of money NMS spends on yearbooks proportional to the total number of yearbooks NMS buys?

• Yes

• No

Does the table represent a proportional relationship?

• yes

• no