Proportional Relationships with Variables

Write an equation using the constant of proportionality.

• y = 5x

• y = 4x

• y = 8x

Suzy is participating in a walkathon. She writes the equation m= 3d +50 to represent the amount of money she collects from each sponsor for walking d kilometers. What number represents the rate of change?

• 50

• 3

• 0

• 1

Proportional relationships must go through the origin. (0,0)

• True

• False

What is the rate of change for the following graph?

• 80 mph

• 20 mph

• 40 mph

• 160 mph

Does this relationship represent a linear relationship?

• Yes

• No

Is the graph proportional or non proportional? Assume it is going through point (0,0).

• Proportional

• Non-Proportional

Which statement best describes the relationship of x and y in the table? Hint: Find the ratio between y and x. If it is constant, that value is the Constant of Proportionality (AKA: Unit Rate) and the relationship is proportional. You can determine if it is constant by dividing y by x for every (x,y) pair. Money/Hours. (k=y/x) If the quotient is the same for every ratio of y/x, then the relationship is proportional and the quotient is the Constant of Proportionality.

• Proportional

• Not Proportional

Write the equation for the table. Find the Constant of Proportionality. (k=y/x; k represents the Constant of Proportionality) Then, put it in the form y=kx. *REMEMBER: k is the Constant of Proportionality.

• y = 1/3x

• y = 3x

• y = 1/2x

• x = 3y

Does the table show a proportional relationship?

• Yes

• No

What is the constant of proportionality (in miles per hour) based on the table?

• 45

• 90

• 135

• 2