A school store tracked daily temperature and ice pop sales. On sample days, 68 degrees led to 22 sales, 72 to 31, 76 to 39, 81 to 48, and 85 to 55. The article gives these values: 68 degrees, 22 sales; 72 degrees, 31 sales; 76 degrees, 39 sales; 81 degrees, 48 sales; 85 degrees, 55 sales. The store wants readers to see the relationship between temperature and sales, not the order of the days. Which graphic should the writer use to show the association?