Linear model project: Analysis of the population of Fairfax County, VA from 1970 - Present.
Data source is http://www.fairfaxcounty.gov/demogrph/gendemo.htm#pop
|
Year
|
Population
|
|
1970
|
454,275
|
|
1980
|
596,901
|
|
1985
|
668,300
|
|
1990
|
818,584
|
|
1995
|
879,401
|
|
2000
|
969,749
|
|
2001
|
984,366
|
|
2002
|
1,004,435
|
|
2003
|
1,012,090
|
|
2004
|
1,022,298
|
|
2005
|
1,033,646
|
|
2006
|
1,037,311
|
|
2007
|
1,041,507
|
|
2008
|
1,045,694
|
|
2009
|
1,051,990
|
|
2010
|
1,081,726
|
|
2012
|
1,109,725
|
|
2015
|
1,124,131
|
|
2020
|
1,158,764
|
|
2025
|
1,213,091
|
Tasks:
Task 1 Plot the points (x, y) to obtain a scatterplot. Use an appropriate scale on the horizontal and vertical axes and be sure to label carefully.
Task 2 Find the line of best fit (regression line) and graph it on the scatterplot. State the equation of the line.
Task 3 State the slope of the line of best fit. Interpret the meaning of the slope in a sentence or two.
Task 4 Find and state the value of r2, the coefficient of determination, and r, the correlation coefficient. Discuss findings in a few sentences. Is r positive or negative? Why? Is a line a good curve to fit to this data? Why or why not? Is the linear relationship very strong, moderately strong, weak, or nonexistent?
Task 5 Choose a value of interest and use the line of best fit to make an estimate or prediction. Show calculation work.
Task 6 Write a brief narrative of a paragraph or two. Summarize findings and be sure to mention any aspect of the linear model project (topic, data, scatterplot, line, r, or estimate, etc.) that you found particularly important or interesting.