The horizontal axis of the graph shows the quantity of units sold in a day. It ranges from 0 to 15 in increment of 5. The vertical axis shows the price per unit in dollars. It ranges from 0 to 60 in increment of 10. A line labeled as S is drawn diagonally upward starting at a point close to x =4. Another line labeled as D0 is drawn diagonally downward starting at a point close to y=30. These two lines intersect at a point whose coordinates are (5,20).

A third line is drawn diagonally downward starting at a point close to y=50. This line is labeled as D1. The line D1 intersects the line S at a point whose coordinates are (7,40).

The difference in price value between the two intersections on the S curve is 20 dollars. This value is labeled on the ...

Get Foundations of Economics, 8th Edition now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.