Project 25
Project description

In this project, use the model that you set up in Project 9, which you used again in Project 19.

  1. Perform the standard regression diagnostics on this model to assess its suitability and the correctness of your hypothesis tests and/or confidence intervals. For any of the regression assumptions that do not hold, comment on what changes this should direct you to in your analysis.
  2. Do the same for a model involving only smaller cities and towns, as you explored in Part c of Project 19.

Background on the data set

The data consist of the April 1, 2007 populations and land areas of the 281 cities and towns of Washington State, obtained from the 2007 Washington State Data Book.

There are some "incorporated and unincorporated" areas in Washington state (with a total population of approximately 5.9 million in 2000) not included in this list of cities and towns. Also, the website notes that: "Land area by city was derived from a 1980 survey of cities with annexed territory added. Some of the city provided 1980 land areas are not accurate. Some land areas have been corrected. Others will be corrected."

Data Source: Washington State Data Book website, maintained by the Office of Financial Management for the State of Washington. (Accessed August 31, 2008.)

Variables in the data set
The variables in the data set are as follows:
NameUnitsDescription
name(municipality name)name of Washington municipality
populationpeoplenumber of residents
areasquare milesarea of municipality
Link to the data set
The full data set in csv format is at:
http://hoard.projectivespace.com/datasets/WAmunicipalities2007.csv