please answer in the image below? [the question:] Melanie buys 2 shells for $0.80. Rosi buys 3 shells for $1.20. Carlos buys 4 shells for $1.60. Use the graph to determine whether there is a proportional relationship between the number of shells and their cost. If so, what does the constant of proportionality mean in this situation? Use the drop-down menus to show and explain your answer.