Short description: Four graphs. The first two graphs represent good X and the next two represent good Y. Long description: The first two graphs represent good X. In the first graph, the horizontal axis representing units of good X ranges from 0 to 10, in increments of 1. The vertical axis representing M U subscript X ranges from 0 to 18, in increments of 2. Graph (a) shows a line that passes through the following points: (1, 16), (4, 10), and (9, 0). In the second graph, the horizontal axis representing units of good X ranges from 0 to 10, in increments of 1. The vertical axis representing T U subscript X ranges from 0 to 80, in increments of 10. Graph (b) shows a curve that passes through the following points: (1, 15), (3, 40), (4, 52), and (9, 75). In the third graph, the horizontal axis representing units of good Y ranges from 0 to 10, in increments of 1. The vertical axis representing M U subscript Y ranges from 0 to 10, in increments of 2. Graph (c) shows a line that passes through the following points: (1, 9), (2, 8), (4, 6), (6, 4), and