Sample Response: When you graph the equation, you get a straight line that passes through the origin, which means the relationship is proportional. The constant of proportionality is the y-value when x = 1, which is 1 5 . Which did you consider in your response? Check all that apply.The graph of a proportional relationship is a straight line.The graph of a proportional relationship passes through the origin.The constant of proportionality is the y-value when x = 1.