What does life expectancy refer to in a population?

Life expectancy is a crucial demographic measure used to assess the average duration that members of a population are expected to live, based on statistical analysis of mortality patterns. This value represents an average figure that accounts for various factors like age, sex, socioeconomic status, and health conditions within the population.

When discussing life expectancy, it specifically refers to the average number of years remaining for individuals in a particular cohort, which is why the correct answer pertains to the average number of years that members are expected to live. This measure can vary significantly between different populations or regions due to health care systems, lifestyle, and environmental factors.

Other options, while related to aspects of population mortality and demographics, do not accurately define life expectancy. For instance, describing the percentage of individuals living beyond a certain age does not convey the average lifespan and could vary greatly among different populations. The total number of years lived by all population members pertains more to overall mortality statistics rather than life expectancy. Finally, while predicting the lifespan of a population at birth may involve elements of life expectancy, it does not fully encompass the concept, as life expectancy can change over time and be influenced by many factors beyond just birth statistics.