Final answer:
The term for the proportion of individuals in the various age classes for any one year is age structure. In the context of the U.S. population, the age structure can be represented by the three pie graphs in Figure A6 that illustrate the division of the total population into three age groups for different years.
Step-by-step explanation:
The term for the proportion of individuals in the various age classes for any one year is age structure. It is the distribution of the proportion of population members in each age class.
In the context of the U.S. population, the age structure can be represented by the three pie graphs in Figure A6 that illustrate the division of the total population into three age groups for different years.