I chose to compare Brazil and Mexico.

Brazil:

Males per 100 Females: 97.1

People per square kilometer: 25.2

Number of children per woman: 1.7

Current Population: 210.3 Million

Estimated Population 2050: 232.3 Million

Mexico:

Males per 100 Females: 96.1

People per square kilometer: 65.5

Number of children per woman: 2.2

Current Population: 127.3 Million

Estimated Population 2050: 150.6 Million

Brazil's population pyramid is stage 4, and is more heavy on the male side than the female side, with no major differences between the sexes otherwise, with a majority of the population being aged 30-39. In contrast, Mexico's pyramid is a stage 3 with a much larger number of males in younger demographics, but transitioning to majority female in older demographics. This indicates that in the past, young men in Mexico have died more often than women, and though that is also true for Brazil, it is not nearly as marked in the graph. Brazil will experience a lower birth rate in the next 30 years, as they have reached a trough in the population pyramid, while Mexico is in the middle of a spike in the birth rate meaning that their population will increase at a faster rate for longer.