Decide whether a relationship is proportional using a graph and a quotient. Decide whether a relationship is proportional using a graph and a quotient. Understand that due to measurement error, if a graph of two associated quantities is close to a line through the origin, or quotients are close to each other, there might be a proportional relationship. Understand that due to measurement error, if a graph of two associated quantities is close to a line through the origin, or quotients are close to each other, there might be a proportional relationship.