Final answer:
A population pyramid is the best tool for visualizing and comparing a population's age and sex composition, consisting of two bar graphs representing male and female age cohorts. Bars in a population pyramid may narrow with increasing age, reflecting decreasing population numbers due to mortality. Bar graphs can also show percentages of population segments to represent demographic data effectively.
Step-by-step explanation:
A population pyramid is a powerful tool for visualizing and comparing a population's age and sex composition. This graphical representation usually consists of two back-to-back bar graphs, one for each sex (male and female), which display the distribution of various age cohorts. Reasons for the bars becoming narrower from younger to older ages in a population pyramid generally reflect the natural decrease in population numbers due to mortality as people age.
Population data can be represented in different ways through bar graphs as well. For instance, in one version, bars show the total number of persons in each age bracket for each year, and in another variation, the bar graphs are set to measure percentages of the population instead of the raw number of persons, adjusting their heights so each bar is divided according to the percentage of the population in each age group.
An understanding of population demands and demographic statistics is critical for analyzing the needs and growth patterns of a country, which can be effectively illustrated with a population pyramid.