Name _______________________________________ Class _______ Date _______________
Inquiry Activity • Paper and Pencil
Chapter 8
Problem
Interpreting Age Structure
What can the age distribution of a country tell you about its population?
Background
Age Structure Graphs
The graphs below show age distribution of China’s population in 1990, and 2010.
In 1990, the number of 20–24 year olds is about 60 million each for males and
females. In 2010, this same group of individuals, now 40–44 years old, is almost
the same size. This indicates that the death rate was low for that group. When death
rates remain low as a population ages, a pyramid-shaped graph will begin to look
more house-like. The data also shows a sharp decrease in the 0–4-year–old
segment of China’s population between 1990 and 2010. A lower birthrate might
explain the change from 1990 to 2010 for that age group.
Trends in Age Structure
Typically, developing countries have high birthrates and high death rates, resulting
in age structure graphs that are broad pyramids with wide bases. Developed or
industrialized nations have lower birthrates and lower death rates, resulting in
graphs that look more like a house with a pointed roof. In this activity, you will
prepare graphs of age structure data for several countries and make inferences
about their demographic stage of development.
Environmental Science • Lab Manual
1
Name _______________________________________ Class _______ Date _______________
Procedure
Materials Computer with spreadsheet software, or blank graph paper
Step 1
Prepare two graphs from the data below using spreadsheet software.
(OPTION: If you are graphing by hand, use graph paper to create age structure
diagrams from the data above. Use a calculator if necessary to help you round
the numbers.)
Population by Age and Sex for
Japan in 2010
Population by Age and Sex for
Haiti in 2010
Age
Male
Female
Age
Male
Female
0–4
2,597,406
2,460,936
0–4
610,054
600,176
5–9
2,970,683
2,815,396
5–9
569,297
559,808
10–14
3,097,351
2,936,348
10–14
563,003
551,371
15–19
3,126,374
2,966,198
15–19
534,625
524,089
20–24
3,345,718
3,189,946
20–24
468,739
461,655
25–29
3,817,825
3,654,724
25–29
384,993
381,705
30–34
4,370,891
4,183,603
30–34
308,676
307,926
35–39
5,057,805
4,859,729
35–39
263,251
257,567
40–44
4,401,791
4,292,902
40–44
234,341
226,302
45–49
3,967,790
3,925,996
45–49
201,029
200,361
50–54
3,794,685
3,805,951
50–54
149,468
162,395
55–59
4,311,023
4,408,454
55–59
95,346
122,662
60–64
4,775,927
5,004,145
60–64
59,438
92,334
65–69
3,852,938
4,262,873
65–69
44,552
74,654
70–74
3,116,404
3,679,326
70–74
34,339
58,024
75–79
2,496,588
3,296,923
75–79
23,339
35,758
80–84
1,648,086
2,572,727
80–84
13,065
17,421
85–89
731,034
1,630,895
85–89
3,993
5,538
90–94
249,446
757,661
90–94
636
959
95–99
61,507
256,876
95–99
65
117
Step 2
If you are using spreadsheet software, enter the data above into a
spreadsheet, or copy and paste the data from the base file provided by
your teacher. Then follow steps 3–7.
Environmental Science • Lab Manual
2
Name _______________________________________ Class _______ Date _______________
Step 3
Format the population values so they are in millions of people; for
example, 1,500,000 becomes 1.5 million. An easy way to do this is to:
• Type an “=” (equals) sign before each value on the spreadsheet.
• Type “/1000000” (without quotation marks) after the value. For
example, the 0–4 category for Japan would be converted from
2,597,406 people to 2.597406 million people.
• Do this for all of the male and female age brackets.
Step 4
Next, add a “–“ sign to each male data entry. Clearly, you can’t have a
negative population, so why add the negative sign? It will cause the
spreadsheet software to display all of the male values to the left of the
y–axis. All of the female values, will be graphed as positive numbers,
and will be displayed to the right of the y-axis.
Step 5
Select all of the data for Japan and open your menu of chart types.
Select “Bar Graph” from the menu and click “Next.” Title the graph
Population by Age and Sex for [Name of Country] in 2010, and label
the x- and y- axes. You may remove gridlines by unclicking under the
“Gridlines” tab. Then, click “Finish.” And finally, to add Male and
Female labels to the legend, choose “Format Data Series” under the
“Options” tab, and re-label Series 1 “Males” and Series 2 “Females.”
Step 6
Now format your graph so that it looks like the example age structure
diagrams of China. To do this, move the y-axis labels to the far left of
the diagram by right-clicking on the y-axis and selecting “Format
Axis.” Then, under the “Colors and Lines” tab, choose “Low” for the
“Tick Mark Labels” position. Next, right-click on one of the data
series and choose “Format Data Series.” Then, under the “Options”
tab, set the “Overlap” and “Gap Width” to 100, and click “OK.”
Check with your teacher and make sure that your graph is properly
formatted. When your graph has been approved, print it out.
Step 7
Repeat Steps 2–6 for the Haiti dataset, but this time set the values to
be in the thousands rather than the millions.
Analyze and Conclude
1. Graph Attach your graph of Population by Age and Sex for Japan in 2010
to your lab report.
2. Graph Attach your graph of Population by Age and Sex for Haiti in 2010
to your lab report.
Environmental Science • Lab Manual
3
Name _______________________________________ Class _______ Date _______________
3. Infer Based on your graphs, describe the stage of development for both
Japan and Haiti. Justify your conclusions.
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
4. Calculate Determine the percentage of Haitians and the percentage of
Japanese below the age of 20 as follows:
• Find the total number of individuals in a country below twenty by adding
together all the males and females in the age categories 0–4, 5–9, 10–14,
and 15–19.
• Find the total number of individuals in a country by adding together all
the males and females in all age categories.
• Find the percentage below twenty by dividing the total number of
individuals below twenty by the total number of individuals and
multiplying by 100.
Percentage below twenty 
total number of individual s below twenty
 100
total number of individual s
__________________________________________________________________________
5. Calculate Determine the percentage of Haitians and the percentage of
Japanese between the ages of 40–59 as above, using data from those age
categories.
__________________________________________________________________________
Environmental Science • Lab Manual
4
Name _______________________________________ Class _______ Date _______________
6. Interpret Graphs Explain what might cause the trends in percentages
observed in Questions 5 and 6 above. What might cause a big change in
oercentages or a small change
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
7. Interpret Graphs Why do the age structure graphs for Haiti and Japan
look the way they do?
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
8. Extension Determine the percentage of individuals below the age of 20 in
both Haiti and Japan that are male. Determine the percentage of individuals
between the ages of 40 and 59 in both Haiti and Japan that are male. Explain
the data. What happens to the initial difference between the percentages as
the population ages?
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
Environmental Science • Lab Manual
5