The graph shows the amount of money paid when purchasing bags of caramel corn at the zoo: a graph is shown. the x-axis is labeled from 0 to 9. the y-axis is labeled from 0 to 10. the four points shown on the graph are ordered pairs 0, 0 and 1, 3 and 2, 6 and 3, 9. these points are joined by a line. the label on the x-axis is bags of caramel corn. the title on the y-axis is total cost in dollars. what is the constant of proportionality? answers are: 3 , one-third , 2 , or one-half