The statement that is true about the relationship represented by the graph is: "It cannot be proportional because when x increases by 2 units, y only increases by 1.5 units." This is because in a proportional relationship, the ratio of the change in x to the change in y should be constant. However, in this graph, as x increases by 2 units, y only increases by 1.5 units, indicating that the relationship is not proportional.