Math 461: Probability Theory (Fall 2023)

An introduction to the mathematical treatment of random phenomena occurring in the natural, physical, and social sciences. Axioms of mathematical probability, combinatorial analysis, random variables and probability distributions, expectation, binomial distribution, Poisson and normal approximation, generating functions and the Central Limit Theorem. We will cover most of the material in the first eight chapters of the textbook.

  • Chapter 1, Combinatorial Analysis, 4 hours
  • Chapter 2, Axioms of Probability (omit sections 2.6, 2.7), 5 hours
  • Chapter 3, Conditional Probability and Independence (omit section 3.5), 5 hours
  • Chapter 4, Random Variables (omit subsection 4.8.4), 6 hours
  • Chapter 5, Continuous Random Variables (omit subsections 5.5.1, 5.6.2, 5.6.4), 5 hours
  • Chapter 6, Jointly Distributed Random Variables (omit sections 6.6, 6.8), 5 hours
  • Chapter 7, Properties of Expectations (omit subsections 7.2.1, 7.2.2, 7.7.1, and section 7.9), 7 hours
  • Chapter 8, Limit Theorems (omit sections 8.4, 8.5, 8.6), 3 hours


Course go.illinois.edu/math461
Grades Canvas
Quiz Prairielearn
Student hours 4-5:50pm Wednesdays + by Appointment.
SyllabusClick here!

Instructor Partha Dey
Office 35 CAB
ContactBy email with subject line: "Math 461:"
Class TR 11:00 - 12:20 pm at 311 Gregory Hall.
TextbookSheldon Ross, A First Course in Probability, 9th Edition, ISBN: 9780321794772.

It is okay to use a different edition for studying.

The books Introduction to Probability Theory by Hoel, Port and Stone; and Probability and Statistics by Morris DeGroot and Mark Schervish are optional as reference texts.

The book Introduction to Probability by C. M. Grinstead and J. L. Snell is available free online.

You can also freely view the ebook Introduction to Probability by Blitzstein & Hwang.
Prerequisite Math 241 or the equivalent. We will use important topics from calculus, such as infinite series with positive terms (most calculations involve the geometric series and series derived from it), improper integrals and double integrals (change of variables formula, manipulating Gaussian integrals).
DRESTo obtain disability-related academic adjustments and/or auxiliary aids, students should contact both the instructor and the Disability Resources and Educational Services (DRES) as soon as possible. You can contact DRES at 1207 S. Oak Street, Champaign, (217) 333-1970, or via e-mail at disability@illinois.edu.
Grading Policy Homework: 20% of the course grade. Homework will be assigned weekly on Thursdays on Canvas, to be submitted at the start of next Thursday lecture or earlier in Canvas.

Solving a lot of problems is an extremely important part of learning probability. You are encouraged to work together on the homework, but I ask that you write up your own solutions and turn them in separately. Late homework will not be graded. If for some reason you've done a homework but can't turn it in online, send it via email before class. Because of this strict policy on late homework, I will drop your lowest score. Please talk to the instructor in cases of emergency.

Quiz: 15% will depend on weekly quizzes on Prairielearn. Problems will be based on that week’s homework material. I will drop your lowest quiz score.

Midterm: 30%=2 x 15% will depend on two in-class midterm exams on (tentatively) Tuesday, Oct 3, 2023 and Tuesday, Nov 7, 2023. Each exam will be technically comprehensive, but emphasizing recent material up to the most recent graded and returned homework assignment. Exam problems will be similar to homework problems.

Final: 35% will depend on a final exam on Friday, Dec 8, 2023 from 8-11am. It will cover the most important topics of the whole course, emphasizing recent material somewhat.
Exam PolicyMake-up exams will be given only for medical or other serious reasons. If you discover that you cannot be at an exam, please let me know as soon as possible, so that we can make other arrangements. You must work completely on your own during exams (and any quizzes). I make my exams fair and similar to homework, so as long as you use the resources provided, you should do fine. If you have difficulties of any kind or fall behind in the course, please come talk to me as soon as possible.
Grading scaleFinal scores will be converted to letter grades beginning with the following scale:
AA-B+BB-C+CD
9390878380777060
As for a curve, these cutoffs might be adjusted, but only in the downward direction (to make letter grades higher).


Week Date Due Content






1 Tu Aug 22 Principle of counting, Permutation, Sec 1.1-1.3
Th Aug 24 Combinations, Binomial and Multinomial Thms. Sec 1.4-1.6






2 Tu Aug 29 Axioms of probability, Sec 2.2, 2.3
Th Aug 31 HW 1 Propositions, Equally likely outcomes, Sec 2.4, 2.5






3 Tu Sep 5 Conditional probability, Sec 3.2
Th Sep 7 HW 2 Bayes Rule, Sec 3.3






4 Tu Sep 12 Independent events and trails, Sec 3.4
Th Sep 14 HW 3 Gambler's ruin, Simpson's Paradox, RVs, Sec 4.1






5 Tu Sep 19 Discrete rvs., Expectation, Sec 4.2-4.4
Th Sep 21 HW 4 Variance. Binomial rv, Sec 4.5-4.6






6 Tu Sep 26 Poisson r.v., Expected value of sums of rvs, Sec 4.7, 4.9
Th Sep 28 HW 5 First Midterm Review






7 Tu Oct 3 MT 1 First Midterm Exam.
Th Oct 5 Geometric, Negative Binomial, CDFs, Sec 4.8, 4.10






8 Tu Oct 10 Continuous rvs and Expectations, Sec 5.1-5.2, 5.7.
Th Oct 12 HW 6 Uniform and Normal rvs, Sec 5.3-5.4.






9 Tu Oct 17 Normal, Exponential and Gamma rvs, Sec 5.4-5.6.
Th Oct 19 HW 7 Joint distributions, Sec 6.1.






10 Tu Oct 24 Independent rvs, Sec 6.2.
Th Oct 26 HW 8 Sums, Conditional distributions, Sec 6.3-6.5.






11 Tu Oct 31 Functions of rvs, Sec 6.7.
Th Nov 2 HW 9 Second Midterm Review.






12 Tu Nov 7 MT 2 Second Midterm Exam.
Th Nov 9 Expectation of rvs, Correlation, variance, Sec 7.2, 7.4.






13 Tu Nov 14 Conditional expectation, mgf, Sec 7.5.
Th Nov 16 HW 10 MGF, Markov and Chebyshev Ineq, Sec 7.7, 8.2.






14 Tu Nov 21 No classes. Thanksgiving break.
Th Nov 23






15 Tu Nov 28 Central Limit Theorem, Sec 8.3.
Th Nov 30 HW 11 SLLN, Jensen's ineq, Sec 8.4-8.5.






16 Tu Dec 5 HW 12 Final Exam review. Last day of class.
F Dec 8 Final Exam.