In the USA, navel oranges are grown primarily in two states: California and Florida. (Arizona also produces oranges, but let's keep the problem simple). Oranges vary in quality, but this is highly regulated by the USDA, so we can consider food-quality oranges as a uniform good of consistent quality regardless of growing location. Furthermore, suppose the USDA regulates the importation of oranges to such an extent that we can ignore imports when we analyze the market for oranges in the USA.

AFC (per box at Capacity of a Location AVC (per box) single grove (boxes Number of groves capacity) per year) California $9 $6 4000 20,000 Florida $6 $7 4000 18,000