Graphing Calculator - Population Growth Project 

Population of Gwinnett County, Georgia, 1900-2000, with linear and exponential growth models.
exponential:
linear:


In this project, you are going to use the Regression functions on your calculator to analyze population growth in Georgia.

  1. Select a county to study. Using the population charts (from www.census.gov), record the population data in lists on your calculator. (STAT - EDIT). Instead of using the actual year, use 0 for 1900, 10 for 1910, and so on.
  2. Make a scatter plot of your data. (2nd STAT PLOT, Zoom 9 to see the whole plot).
  3. Take a look at your graph. Does it look like the data could be modeled with an exponential function? Or does it look more like a linear function?
  4. Do linear, quadratic, cubic or exponential regression (or all of them!) with your calculator, according to which you think will make a better model. (STAT CALC). Be sure that you have DIAGNOSTICS ON so that you can see the r-values.
  5. Write down your equation(s) and r-value(s).
  6. You can put the equation directly into o by doing the following steps:
    1. press  Y=,  VARS,   5:Statistics
    2. use the right arrow to select EQ
    3. Select 1: RegEQ, press Enter.  (Regression Equation)
    4. Your equation will be copied to Y=
    5. press GRAPH to see how well this equation fits your data.
  7. You can use 2nd Draw – Text to type text onto your screen, such as the county name and your name.
  8. Is there anything you want to change? Would your graph be a better fit if you eliminated some of the early decades from your data? Make any changes you wish and re-graph your data.
  9. When you are satisfied with your results, save your graph.
  10.  Next, you are going to do some research about your county’s history  at http://www.cviog.uga.edu/Projects/gainfo/county.htm and see if you can discover why the population increased or decreased at various times.
  11. Analyze your results.  Write a good one-page summary that discusses the growth or decline in population in your county. Look at your equation and determine the percent of increase or decrease and include that in your discussion. What factors do you think might have contributed to the growth or decline? Were there some decades that did not follow the general growth or decline trend? Predict what the population will be in the years  2010 and 2020.