Exploring growth factors in population data How and why populations grow is a key question in environmental science. For
this exercise you will examine and graph current population data for the world
to explore which factors are most strongly correlated with birth rates. To start
this exercise, click on  popdata.xls (42.0K)
Once open, use "Save As" to copy the file to your hard disk. If you have Excel
on your computer you should be able to open the data file by double clicking
on it. (Other spreadsheet programs can also read this file, but you must open
it from within your program, not by double-clicking.) 1. This file contains population data for the countries of the world, sorted
by the United Nations' Human Development Index (HDI) rank. First look at the
top twenty countries. Where are they? What is the range of income levels (in
GNP per capita) of the top twenty? What is the range of income for the bottom
twenty countries? 2. Now make the following graphs. Detailed instructions for making graphs in
Excel are included at the far right side of the spreadsheet page (column N).
a. First make an X,Y scatter graph of Adult Literacy and Births Rate. How would
you describe the relationship between these variables? How would you explain
this relationship?
b. Keep this graph in your spreadsheet while you make three more scatter graphs:
GNP per Capita and Birth Rate,
Life Expectancy and Birth Rate
Infant Mortality and Birth Rate.
Describe the trends you observe and explain what they mean. 3. How would you compare the relative amount of scatter in each of the graphs
you've made? Why do some curves slope from right to left while others slope
the opposite direction. If you draw a line through the middle of the cluster
of dots, some curve smoothly while others seem to have a break or inflection
point. How would you interpret these patterns? 4. Try changing the shape of your graphs. (See instructions on the right side
of the spreadsheet to do this.) If you make the graphs taller or wider, how
does it affect the way your trends look? How could you deliberately manipulate
the shape to affect other peoples' interpretation of the data? Is this ethical?
Have you ever seen it done? 5. Now make a dot graph of GNP Per Capita and Adult Literacy. Is there a linear
relationship between the two variables? Why or why not? | 
2002 McGraw-Hill Higher Education