Proportional and Nonproportional Relationships

Proportional and Nonproportional Relationships

7th Grade Chapter 1 Lesson 4

Proportional Relationships

• They have a constant ratio

• They have a constant unit rate

Multiple Select

Select all of the examples below that you think show proportional relationships between two ratios:

• $\frac{1}{2}=\frac{4}{8}$

• $\frac{1}{4}=\frac{2}{5}$

• $\frac{1}{3}=\frac{3}{9}$

• $\frac{4}{9}=\frac{8}{13}$

What is a proportional relationship?

*A proportional relationship is a relationship in which the ratio between the two quantities is equivalent for all values.

*Write each row as a fraction. Reduce. Make sure they are all equivalent.

*The table on the right represents a proportional relationship.

Disregard (0,0) for now.  If you write each row as a fraction, you will get the following:

 $\frac{1}{3}\ \ =\ \frac{2}{6}\ =\ \ \frac{3}{9}\ =\ \frac{4}{12}$  

Open Ended

What do you notice about the table?

Write down at least two things that you notice in the table.

(Click to enlarge the picture if needed)

Multiple Choice

Is this table proportional?

• yes

• no

• I'm not sure, I need extra help!

Multiple Choice

Which statement best describes the relationship of x and y in the table?

• Proportional

• Not Proportional

Multiple Choice

Is this table proportional or non-proportional?

• Proportional

• Non-Proportional

• both

• neither

Poll

A cleaning service charges $45 for the first hour of work and $30 for each additional hour. Is the total cost proportional to the numbers of hours worked?

• Yes

• No