ECEN 3810 ‑ Introduction to Probability

 

FALL 2006

 

Department of Electrical and Computer Engineering

 

University of Colorado-Boulder

 

 Announcements

 Administrative Information

 Course Details

 Homework and Solutions

 

 

 

Announcements

 

 

Date

 

Announcement

11/12/06

Recitation class tomorrow at EE 1B28 from 6 to 7 pm for HW 15

11/7/06

Recitation Class today at EE1B28 from 6 pm to 7 pm for Practice Questions for  2nd Midterm

11/1/06

Recitation Class tomorrow at EE265 from 6 pm to 7 pm for HW 10

10/16/06

Recitation Class tomorrow at EE1B28 from 6 pm to 7 pm for HW 7

10/9/06

Recitation Class tomorrow at EE1B28 from 6 pm to 7 pm for HW 6

 

29/9/06

 

Recitation Class today at EE1B28 from 6 pm to 7 pm for HW 5

 

22/9/06

 

Recitation Class today at EE1B28 from 6 pm to 7 pm for HW 4

 

17/9/06

 

Recitation Class tomorrow at EE1B28 from 6 pm to 7 pm for HW 3

 

12/9/06

 

Recitation Class today at EE1B28 from 6 pm to 7 pm for HW 2

 

 

Administrative Information

 

Instructor:   Mahesh Varanasi

                    Room:   ECOT 333 , Engineering Center

                    Phone :  (303) 492‑0258

                    Email: varanasi@colorado.edu

       Office hours: 5:30-7:30 pm MW, 3:00-4:00 pm F

 

Teaching Assistant: Rajesh T Krishnamachari

                                 Room : ECEE 150, Engineering Center

                                 Phone: (303) 492-2759

                                 Email: krishnrt@colorado.edu

                                 Office hours: F 4-5 pm

 

Course web site: 

 

Lecture Timings: MWF 2-2:50 pm, DUAN G 125

Recitation Class Timings: One of MTF 6-7 pm, EE 1B28

 

Course Details             

 

Course Catalog Description: Covers the fundamentals of probability theory and treats the random variables and random processes of greatest importance in electrical engineering. Provides a foundation for study of communication theory, control theory, reliability theory, optics, and portfolio analysis.

 

Course Objectives: To teach and learn model building, rigorous probabilistic reasoning and analysis, and probability calculations in the context of electrical and computer engineering. To solve problems in gambling, quantizing, communicating, estimating, and quality control.

 

Prerequisites: APPM 2350, Calculus 3, and APPM 2360, Linear Algebra and Differential Equations.

 

Required ‑ 3 credit hours

 

Required Textbook: Probability and Stochastic Processes (2nd Edition), Yates and Goodman, John Wiley and Sons;

Reference Textbook: A first course in Probability (7th Edition) by Sheldon Ross, Prentice-Hall Engineering

 

Much of our life is based on the belief that the future is largely unpredictable. For example, we wouldn’t watch games of chance such as in the U.S. Open or World Cup Soccer or listen to political pundits talking about the upcoming mid-term elections on TV if we knew the outcomes in advance. We talk about our belief in this unpredictability by using words like “random”, “possibility”, “likelihood”, “risk”, “luck”, ”probability”, etc. and rely on our gaming and other experience of the world around us to assign qualitative and quantitative  meanings to such usages. In this course, we are interested in constructing a mathematical theory of probability that will incorporate the concepts of chance which are contained implicitly in common rational understanding. Such a theory will formalize these concepts as a collection of axioms, which should lead directly to conclusions that are consistent with practical experimentation.

 

Here are some representative problems from probability theory:

 

1. Factory 1 makes twice as many resistors as factory 2 in a week. 20 % of its circuits are defective (the actual resistance value differs by more than 50  of the stated value) whereas 5 % of those manufactured by factory 2 are defective. What is the probability that you’d buy a non-defective resistor?

 

2. A man is saving up to buy a new BMW at a cost of N units of money. He starts with k units, 0 < k < N, and tries to win the remainder by the following gamble with his bank manager. He tosses a coin repeatedly; if it comes up heads, then the manager pays him one unit, if it comes up tails, he pays the manager one unit. He plays this game repeatedly until one of the two events happens that either he runs out of money or he wins enough to buy the car. What is the probability that he’ll be ultimately bankrupted?

 

3. You wish to ask each of a large number of people to which the answer “yes” is embarrassing. The following procedure is proposed in order to determine the embarrassed fraction of the population. As the question is asked, a coin is tossed out of sight of the questioner. If the answer would have been “no” and the coin shows heads, then the answer “yes” is given. Otherwise, people respond truthfully.

• a. Can you estimate the fraction of embarrassed people this way? if so, what is your estimate?

• b. What is the smallest number of people the examiner must question in order to claim the probability that his estimate is within 5 % of the true value is not less than 0.95? Assume here that the examiner knows that the true value of the embarrassed fraction lies somewhere in the interval [0.25, 0.75] ?

 

4. You roll 6n dice once; you need at least n sixes. Your friend rolls 6(n+ 1) dice and he needs at least n + 1 sixes. Who is more likely to obtain the number of sixes he needs?

 

Grading:

– 25% Homework (Approx. 1 homework per week)

– 10% Pop Quizzes (2-3 during the semester, 20 minutes each)

– 15% Mid Term I (Oct 4, ’06 from 2-2:50 pm; no class this day)

– 20% Mid Term II (Nov 8, ’06 from 2-2:50 pm, no class this day)

– 30% Final Exam (Dec 18, ’06 from 4:30-7:00 pm)                                   

 

 

Homework and Solutions

 

HW 1 Questions

HW 1 Solutions

HW 2 Questions

HW 2 Solutions

 

    HW 3 Questions

 

          HW 3 Solutions

 

    HW 4 Questions

  

        HW 4 Solutions

 

 

   HW 5 Questions

 

 

HW 5 Solutions

 

 

Practice Midterm Qs

 

Practice Midterm Solutions

HW 6 Questions

HW 6 Solutions

     HW 7 Questions

           HW 7 Solutions

     HW 8 Questions

           HW 8 Solutions

     HW 9 Questions

          HW 9 Solutions

    HW 10 Questions

           HW 10 Solutions

2nd Midterm Practice

Questions

      2nd Midterm Practice Answers

    HW 11 Questions

           HW 11 Solutions

   HW 12 Questions

         HW 12 Solutions

   HW 13 Questions

      HW 13 Solutions

   HW 14 Questions

        HW 14 Solutions

    HW 15 Questions

       HW 15 Solutions

Practice Final Exam

   Practice Final Solutions