SOLUTION
What matters is not the absolute abundance of factors, but their relative abundance. Poor countries have an abundance of labor relative to capital when compared to more developed countries. For example, consider a large, rich country like the United States and a small, poor country like Guatemala. Though the United States has more land, natural resources, capital, and labor than Guatemala, what matters for trade is the relative abundance of these factors. The ratio of labor to capital is likely to be much higher in Guatemala than in the United States, reflecting a relative scarcity of capital in Guatemala and abundance in the United States. This makes labor relatively cheaper and capital more expensive in Guatemala than in the United States. Notice that this difference in factor prices is not driven by how much labor Guatemala has compared to the United States, but by the proportion of labor to other factors.