Final answer:
Life expectancy has a strong relationship with Gross Domestic Product (GDP), as higher GDP often correlates with better access to healthcare and a higher standard of living, which together contribute to longer lifespans.
Step-by-step explanation:
According to the textbook information provided, there is a strong relationship between life expectancy and Gross Domestic Product (GDP). Countries with higher GDPs often have a higher standard of living, which includes access to high quality healthcare and lower birth rates. These factors invariably affect life expectancy, as they contribute to a healthier and more sustainable population environment. Furthermore, when the GDP is divided by the population, yielding the GDP per capita, this measure tends to be higher in countries with higher life expectancies due to their lower population growth rates and higher productivity.
When studying the map on global life expectancies, one would notice that countries with higher life expectancy rates are often those with higher GDPs and better-developed healthcare systems. This suggests that economic prosperity is closely linked to longer, healthier lives. Additionally, a decline in infant mortality, which is not directly counted in GDP, contributes to the overall standard of living and can lead to an increase in average life expectancy.