The cost of chicken at store M is represented by the equation y = 4.09x, where x is the number of pounds of chicken sold and y is the total cost. The cost of chicken at store N is shown in this table. Number of Pounds of Chicken (x) Total Cost (y) 3.25 $13 4.50 $18 5.75 $23 6.25 $25 What is the difference in the cost per pound of chicken at stores M and N?