Please refer to the curved line in figure 16-3 on page 667 and explain the reason for the following: The line initially has an upward slope, but gradually begins to slope downward as you move further out along the horizontal axis. Please refer to the curved line in figure 16-3 on page 667 and explain the reason for the following: The line initially has an upward slope, but gradually begins to slope downward as you move further out along the horizontal axis