Proportional Relationships with Graphs, Tables, and Equations

Kenny is practicing for at typing test. The number of words he can type is proportional to the number of minutes he types. If Kenny types for 18 minutes, how many words will he be able to type?

Does the table represent a proportional relationship?

• Yes.

• No.

Does this graph represent a proportional relationship?

• Yes

• No

The table shows a proportional relationship. Which of the following is the equation for the number of cookies, c made with each cup of sugar, s

• s = 12c

• s = 24c

• c = 12s

• c = 24s

Answer explanation

Divide the y value in the ratio by the x value to get the constant.

Remember the top row is the x and the bottom row is the y in the ratio.

Proportional equations are written y=kx where k is the constant of proportionality.

Replace the x and y with variables they represent in the ratio.

Does the table represent a proportional relationship?

• Yes.

• No.

The number of trees and the number of apples are given in the table above.  Determine which statement below is correct.

• The table is not proportional because the unit rate is not constant.

• The table is proportional and the unit rate is 1/13

• The table is proportional and the unit rate is 13.

• The table is not proportional because it doesn't pass through the origin.

Using the graph above, determine the constant of proportionality.

• k = 0

• k = 1

• k = 3

• k = 6

Using the table above, determine which statement is correct.

• The table is proportional and the unit rate is 100.

• The table is not proportional because the unit rate is not constant.

• The table is not proportional because it doesn't pass through the origin.

• The table is proportional and the unit rate is 0.01.

The graph above shows the price of games in dollars.  Is the graph proportional and how do you know?

• The graph is proportional  because it is linear.

• The graph is proportional because it is linear and passes through the origin.

• The graph is not proportional because it does not pass through the origin.

• The graph is not proportional because it is not linear and it does not pass through the origin.

Determine if the table above is proportional and how do you know?

• The table is proportional because the unit rate is a constant 0.33.

• The table is proportional because it passes through the origin.

• The table is proportional because the unit rate is a constant 0.28

• The table is not proportional because the unit rate is not constant.