Linear Models

 

[The Homework Assignments]
Homework Assignments

While each of the following assignments has their own specific purpose, the general purpose of any homework is to give you practice in the material covered in class (and its extensions) and to give you honest feedback on your work. As such you need to see these as oportunities to show off all you know in terms of writing, calculations, and presentation.

The parenthetical statement above, “and its extensions,” is there for a reason. I am not the font of all knowledge. When you leave Knox, your job will give you problems you never saw here. You need to build skills in understanding solutions of problems sent to you.

[LaTeX] Note that all assignments are due at the start of the class period. Also all assignments need to be printed and physically handed in to Dr. Forsberg. These are due on Wednesdays. The Wednesday due date allows you to work on these over the weekend, ask questions on Monday, and finish on Tuesday.

Please typeset your solutions nicely in LaTeX and submit a hardcopy to the professor at the start of the class. If you email them, there will be a 25% cost. If you do not use LaTeX, there will be a 25% cost. If I suspect you are not using LaTeX, I will ask you to email your tex file.

[you are fired] On the job, you will often have due dates that you cannot miss without costing the company thousands (or millions) and receiving a pink slip. People will depend on you to be punctual in all aspects. Treat this class in the same way. Build good habits now: Be on time.

 

The Assignments

Here are the homework assignments for this course. Please refer to the syllabus for how these relate to your grade. Please contemplate the skills being exercised in these to understand how these relate to your fundamental understanding of the material in this course.

 

Assignment 1: January 10

Appendix M problems: 7, 8, 9, 10, 11.

Assignment 2: January 17

Appendix S problems: 1, 3, 7, 9, 10.

Assignment 3: January 24

Chapter 2 problems: 2, 3, 4, 6, 7.

Assignment 4: January 31

The following five problems:

  1. Calculate \( V[\textbf{b}]\) when there is no variation in the x values.
  2. Prove that the vectors \(\hat{\textbf{Y}}\) and \(\textbf{E}\) are orthogonal.
  3. Prove that the matrix \( \textbf{I} - \textbf{H} \) is symmetric idempotent.
  4. Directly prove that \(\textbf{X}\) of Eqn 2.149 (page 47) is rank deficient (has rank less than 4) by finding the coefficients, \(a_i\), such that \( \sum_i\ a_i \textbf{X}_i = \textbf{0} \) for columns \( \textbf{X}_i \) and scalars \( a_i \), not all zero.
  5. First, determine circumstances when the model’s \(R^2 = \bar{R}^2\). Second, create a set of data (\(n = 5\)) such that \(R^2 = \bar{R}^2\). Note that \(p > 1\) for everything we do.

Assignment 5: February 7

Day of Dialog. No classes. No assignment due.

Assignment 6: February 14

Chapter 3 problems: 1, 2, 8, 9, 10.
Also this problem:

Using the big12football2015 data set, is there a significant relationship between the number of points scored by the team (ptsFor) and the number of points scored by its opponent (ptsAgainst)? Make sure you check the requirements correctly. The URL for the data set is

http://rur.kvasaheim.com/data/big12football2015.csv

Note that you have a lot of techniques available to you at this point. Be very clear on what you do. Tell a narrative.

Assignment 7: February 21

Link to Assignment 7.

Assignment 8: February 28

Link to Assignment 8.

Assignment 9: March 7

No assignment this week.

 

This page was last modified on 16 November 2023.
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