The graph shows the prices, in dollars, of different numbers of pies at Erik's store. The table shows the prices, in dollars, of different numbers of doughnuts at the same store. A graph shows Number of Pies on x-axis and Price of Pies on y-axis. The x-axis scale is shown from 0 to 12 at increments of 2, and the y-axis scale is shown from 0 to 160 at increments of 20. A straight line joins the ordered pairs 2, 20 and 4, 40 and 6, 60 and 8, 80 and 10, 100 and 12, 120. Doughnuts Number of Doughnuts Price of Doughnuts (dollars) 2 6 4 12 6 18 8 24 How many dollars more is the price of a pie than the price of a doughnut at Erik's store? $2 $3 $6 $7