#### Transcript of Unit 1 Lesson 5: Identify proportional and non-proportional

**Unit 1 Lesson 5: Identify proportional and non-proportional relationships in graphs**

7th Grade Math

Student Outcomes

Students decide whether two quantities are proportional to each other by graphing on a coordinate plane and observing whether the graph is a straight line through the origin.

Students study examples of quantities that are proportional to each other as well as those that are not.

Use the ratio table and identify if the two quantities are proportional to each other and give reasoning for your answer.

Try these 2 on your own

The two quantities are not proportional to each other because a constant describing the proportion does not exist.

Both graphs can have points that lie in a line but the graph of the quantities that are proportional to each other must also go through the origin. Example 3 will not have a proportional relationship.

The graph could go through the origin, but if it does not lie in a straight line, it does not represent two quantities that are proportional to each other. So Example 2 will not have a proportional relationship.

How are proportional quantities represented in a graph?

They are represented in a graph where the points lie on a straight line that passes through the origin.

What is a common mistake a student might make when deciding whether a graph of two quantities shows that they are proportional to each other?

Both graphs can have points that lie on a straight line, but the graph of the quantities that are proportional to each other also goes through the origin. In addition the graph could go through the origin, but the points do not lie on a straight line.

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