Figure 15-7 Graph (a) Graph (b) Panel A, a graph of Price versus Quantity, shows a straight line, M C, increasing linearly, and a curved line, A T C, decreasing at a decreasing rate to the left of Point C, where M C and A T C intersect, and increasing after that at an increasing rate. A horizontal line extends from P sub 3, passing through A T C at 2 points and M C at 1 point. A horizontal line extends from P sub 2, passing through the intersection of M C and A T C. A horizontal line extends from P sub 1, passing through M C at 1 point. A vertical line extends from Q sub 2 and meets at the intersection of M C and A T C. A vertical line extends from Q sub 3, passes through A T C, and meets at a point on M C, touching the line that extends from P sub 3. P sub 3 is above P sub 2. P sub 2 is at the intersection of M C and A T C, and P sub 1 is below P sub 2. These three prices are determined by