1. Proportional Relationships and Graphs

2. Proportional Relationships and Graphs
The manager of the car paint company prepares orders for its Granny Apple Green paint.
Tell how the graph can help you find the amounts of blue and yellow paint needed to make 8 gallons, 24 gallons, and 56 gallons of Granny Apple Green paint.

3. Proportional Relationships and Graphs
A graph can also be used to show a proportional relationship between two quantities.
The table shows a proportional relationship between time and the number of heartbeats.
Each row of the table can be represented as a ratio.

4. Proportional Relationships and Graphs
Each ratio can also be represented as a point on the graph.
Draw a line through all the points.
Each y-value is 3/2 times the x-value.
This means each time the x-value increases by 2, the y-value increases by 3.
Notice that the line passes through the origin.
A graph that represents a proportional relationship is a straight line passing through the origin.

5. Proportional Relationships and Graphs
Does each graph show a proportional relationship between x and y?

6. Proportional Relationships and Graphs

7. Proportional Relationships and Graphs
Does the equation y = 6x show a proportional relationship between x and y? Explain.
Make a table of values.
Graph the points.
Draw a line through the points. x y

8. Proportional Relationships and Graphs
Does the equation y = 4x + 1 show a proportional relationship between x and y? Explain.
Make a table of values.
Graph the points.
Draw a line through the points. x y

9. Proportional Relationships and Graphs
The graph shows a proportional relationship between time and the distance run by a cheetah.
What does the point (1, 90) represent?
What does the point (0, 0) represent?
How far did the cheetah run in 3 seconds?
Assuming the cheetah continues to run at the same speed, how long would it take the cheetah to run 900 feet?

10. Proportional Relationships and Graphs

11. Focus Question/Exit Ticket
How can you tell if a graph shows a proportional relationship between two quantities?

12. Homework:
Proportional Relationships - Tables and Graphs Worksheet