Stats 101 Spring 2024 Final
Used car report
Assignment instructions
Task
Imagine you have been newly hired by a used car dealer to assess the state of the market for used cars. The dealer’s plan is to send out buyers to states in the American South and pay a premium to buy higher mileage and foreign made cars, vehicles she believes she can sell to her customers for a good profit.
Your job is to write a report that should explain whether the used car dealer’s plan is a good one, and propose any other variables you think the dealer shoul consider when buying used cars. The variable definitions can be found here here.
You will need to use all the material we learned in class to:
- Think carefully about the sampling frame, what your research expectations and questions are, and how the method of data collection can influence your findings
- Interpret summary data
- Examine important bi-variate relationships
- Construct a high-quality regression model of
price
- Interpret this model, including ALL relevant diagnostics and \(p\) values.
- Propose a plan to the dealer of what cars to focus on and why
Specific requirements
- Save this document as a new document (Save As…) and rename it
Used car report
. - Rename the title of your report to
Used car report
- Delete the
Assignment instructions
section - Final report should be between 2000 and 3000 words
- Maximum 8 graphs
- Maximum 6 tables
- Suggested structure:
- Introduction
- Literature review and hypotheses
- Summary statistics
- Regression interpretation
- Regression diagnostics
- Interpret coefficients
- Conclusion
Points of emphasis
Your job as an analyst is to write a report primarily analyzing what are the factors you think best predict
price
according to the dealer requirements and any other factors you judge important (which you may develop from reviewing the literature on the subject and based on your views of the summary data).Do not exclude a variable just because it initially does not meet the regression requirements. However, consider carefully whether some variables are actually highly related to another predictor variable – do not include collinear variables.
You should focus your graphs and tables on that illustrating the most important information for drawing your conclusion. Choose your tables carefully such that they convey the key information needed to arrive at your conclusion. Do not make tables and graphs of irrelevant information or points that do not need discussing.
Make sure to also interpret the coefficients. You need to interpret the impact of a one unit change in the coefficients on the response variable. You additionally need to examine whether changes in the predictor variables lead to a substantively large or small change in the predictor variable. One way to do this is examining whether changing the predictor variable from its Q1 to Q3 value leads to a large or small change in the response variable. You may want to make a table with this information.
Your report should be a polished, quality product that you would be proud to show your boss/employer. No unnecessary printed code, poorly labeled graphs, or strange looking formatting. Use everything you have learned in this class to make a quality final product! Remember, this document is not a formal essay. Some of the differences between a business report and a formal essay are summarized in the table below and by this link: