LESSON 5: Identifying Proportional and Non-Proportional Relationships in Graphs

Dr. Basta 1

Candy Bars Sold Money Received ($)2 34 58 912 12

Isaiah sold candy bars to help raise money for his scouting troop. The table shows the amount of candy he sold to the money he received.

Is the amount of candy bars sold proportional to the money Isaiah received?

How do you know?

Dr. Basta 2

LESSON 5: Identifying Proportional and Non-Proportional Relationships in Graphs

2 3

4 6

6 9

8 12

Characteristics of graphs of proportional relationships:

•Points lie in a straight line. •Line goes through the origin.

What is the origin and where is it located?

The intersection of the x and y axis, at the ordered pair (0,0).

Dr. Basta 3

LESSON 5: Identifying Proportional and Non-Proportional Relationships in Graphs

1. The following table gives the number of people picking strawberries in a field and the corresponding number of hours that these people worked picking strawberries. Graph the table. Does the graph represent two quantities that are proportional to each other? Explain why or why not.

1 3

7 1

4 2

Dr. Basta 4

LESSON 5: Identifying Proportional and Non-Proportional Relationships in Graphs

2. Fill in the table and given values to create quantities proportional to each other and graph them.

4 2

Dr. Basta 5

LESSON 5: Identifying Proportional and Non-Proportional Relationships in Graphs

3a. What are the differences between the graphs in Problem 1 and 2?

3b. What are similarities in the graphs in Problem 1 and 2?

3c. What makes one graph represent quantities that are proportional to each other and one graph that does not represent quantities that are proportional to each other in Problems 1 and 2?