Which graph shows a proportional relationship? On a coordinate plane, points (2, 3), (3, 8), and (6, 9) are plotted. On a coordinate plane, points (2, 4), (3, 6), and (5, 10) are plotted. On a coordinate plane, points (1, 3), (4, 4), and (5, 10) are plotted. On a coordinate plane, points (2, 9), (5, 4), and (9, 3) are plotted.