The opportunity cost of a pound of almonds in Yosemite is 1/2 pound of basil, whereas the opportunity cost of a pound of almonds in Rainier is 3/2 pounds of basil. Therefore, Yosemite has a comparative advantage in the production of almonds. (Note: One way to find the opportunity cost of a pound of almonds in Yosemite is to examine how many pounds of almonds Yosemite can produce if it produces only that good and then determine how many pounds of basil it gives up: 36 million pounds of basil72 million pounds of almonds=1/2 pound of basil per pound of almonds.)
The opportunity cost of a pound of basil in Yosemite is 2 pounds of almonds, whereas the opportunity cost of a pound of basil in Rainier is 2/3 pound of almonds. Therefore, Rainier has a comparative advantage in the production of basil.
When the two countries specialize, Yosemite will produce 72 million pounds of almonds, and Rainier will produce 72 million pounds of basil because Yosemite has a comparative advantage in producing almonds and Rainier has a comparative advantage in producing basil.