## Graphs of Proportional Relationships

#### Aligned To Common Core Standard:

**Grade 7 Proportional Relationships** - 7.RP.A.2d

How to Graph the Proportional Relationships - Proportional relationships are shown by making a graph of those relationships. The main idea behind the graph of a proportional relationship is to make a straight line that goes through the origin. So, the question is, what a proportional relationship is? Many students struggle to answer this question. A proportional relationship is one where the ratio between two variables (let's say X and Y) remains constant. Another way of looking at it can be the value of Y will always be equal to some constant number being multiplied by any value of X. Y = KX Let's take an example of a proportional relationship that can form a graph. X- 1- 4- -2, Y- ½ - 2- -1 Let's take the ratio for all these values X- Y- Y/X 1- ½ - ½, 4- 2- ½, -2- -1- ½ So, it can be seen that ration between X and Y is ½ which shows a proportional relationship. This can lead to a straight line on the graph.

### Printable Worksheets And Lessons

- Nuts Step-by-step Lesson-
Is the price of nuts proportional to the serving size?

- Guided Lesson -
I give you the graph to start with on two of them, but ask you to
create a graph for the second one.

- Guided Lesson Explanation
- These types of problems take some time to answer properly. That
is why it is spread over 3 pages.

- Practice Worksheet
- I tried to have you make the graph as much as possible. You will
need a lot of scrap paper.

- Matching Worksheet - Match the three tables to their constant of proportionality.

#### Homework Sheets

Use both the graph and data table to help it solidify in your mind.

- Homework 1 - Determine if the quantities are proportional. If so, what is the constant of proportionality that defines the relationship?
- Homework 2 - Kelly sold burgers over two days. Create a graph to determine if the quantities of burgers and number of days are proportional. Write an equation to describe this relationship.
- Homework 3 - Jenny eats pizza over time. The quantities are proportional.

#### Practice Worksheets

These problems force you to choose one approach when tackling them.

- Practice 1 - The graph below represents the number of computers sales over some days. What is the constant of proportionality?
- Practice 2 - Ashley brought packs of cookies. Create a graph to determine if the number of packs and price are proportional for each serving size listed in the table. If the quantities are proportional, write a linear equation to describe the relationship.
- Practice 3 - Justin sold book covers over four days. Write a linear equation to express this relationship.

#### Math Skill Quizzes

These quizzes were created with skill mastery in mind. They are a bit challenging for most.