Final answer:
The population density in 1900 was approximately 250 people per square kilometer.
Step-by-step explanation:
The subject of this question is Geography. Population density is a geographical concept that measures the average number of individuals in a population per unit of area or volume. In this case, we are given the information that the population density in 1900 was approximately 250 people per cubic kilometer.
To calculate population density, you divide the total population by the total area or volume. In this case, we are not given the total population, so we cannot calculate the exact population density. However, we are given a range of population densities that correspond to different population categories. Therefore, the population density in 1900 could fall within the range of 150-300 people per square kilometer.