Final answer:
Without a specific legend or explanation for the color coding, we cannot determine what a blue colored bar indicates regarding reproductive age in the bar graph representing U.S. population age distribution.
Step-by-step explanation:
When analyzing bar graphs that represent population data, the color coding is critical for conveying information about different age groups. In the context described where a bar graph shows the U.S. population distribution with a portion colored blue, one needs to refer to the legend or the graph's explanation to understand what that specific color represents. Without that reference, one cannot determine what a blue colored bar signifies in terms of reproductive age. Therefore, the correct answer to what it means if a bar is colored blue is: 2) The answer cannot be determined from the graphs.
Bar graphs, such as those depicted in Figure A8, are effective visual tools because they can illustrate complex data in a simple form, showing totals and percentages of population divided into age brackets. Whether the blue color denotes age groups past reproductive age, of reproductive age, or those not yet at reproductive age can only be determined if that information is provided within the graphs or accompanying text.