Interpreting Constants of Proportionality

Which graph is proportional?

• A

• B

• C and D

• All of the graphs are proportional

A proportional relationship can be written as an equation in the form ____ = _____  _____

• y = k+x

• y = k-x

• y = kx

• y = k/x

Identify the constant of proportionality.

• k = 2

• k = 4

• k = 1/2

• k = 1/4

• none (not proportional)

Identify the constant of proportionality.

• k = 5

• k = 1/5

• k = 1

• k = 2.5

• none (not proportional)

Identify the constant of proportionality.

• k = 25

• k = 50

• k = 100

• k = 1/50

• none (not proportional)

What makes a graph proportional?

• Straight line

• The line goes through the origin

• Curvy line

• Straight line and the line goes through the origin

Determine the constant of proportionality for the table. Express your answer as y = kx

• y = 1/2x

• x = 1/2y

• y = 2x

• k = x

k represents

• the constant of proportionality

• the king

• ketchup

• a strikeout

Determine the constant of proportionality for the table. Express your answer as y = kx

• 33

• y = 1/3x

• y = 33x

• y = 33

Which equation matches the constant of proportionality?

• x = y

• y = x

• y = kx

• l x w