The Erik Jonsson School of Engineering and Computer Science Chapter 6 pp. 243-274 William J. Pervin The University of Texas at Dallas Richardson, Texas.

Slides:



Advertisements
Similar presentations
Let X 1, X 2,..., X n be a set of independent random variables having a common distribution, and let E[ X i ] = . then, with probability 1 Strong law.
Advertisements

Chapter 2 Multivariate Distributions Math 6203 Fall 2009 Instructor: Ayona Chatterjee.
Use of moment generating functions. Definition Let X denote a random variable with probability density function f(x) if continuous (probability mass function.
06/05/2008 Jae Hyun Kim Chapter 2 Probability Theory (ii) : Many Random Variables Bioinformatics Tea Seminar: Statistical Methods in Bioinformatics.
Sep 16, 2005CS477: Analog and Digital Communications1 LTI Systems, Probability Analog and Digital Communications Autumn
Probability Theory Part 2: Random Variables. Random Variables  The Notion of a Random Variable The outcome is not always a number Assign a numerical.
1 Chap 5 Sums of Random Variables and Long-Term Averages Many problems involve the counting of number of occurrences of events, computation of arithmetic.
SUMS OF RANDOM VARIABLES Changfei Chen. Sums of Random Variables Let be a sequence of random variables, and let be their sum:
Time Series Basics Fin250f: Lecture 3.1 Fall 2005 Reading: Taylor, chapter
CSE 221: Probabilistic Analysis of Computer Systems Topics covered: Multiple random variables Transform methods (Sec , 4.5.7)
1 Review of Probability Theory [Source: Stanford University]
Tch-prob1 Chapter 4. Multiple Random Variables Ex Select a student’s name from an urn. S In some random experiments, a number of different quantities.
The moment generating function of random variable X is given by Moment generating function.
2003/04/24 Chapter 5 1頁1頁 Chapter 5 : Sums of Random Variables & Long-Term Averages 5.1 Sums of Random Variables.
The Erik Jonsson School of Engineering and Computer Science Chapter 2 pp William J. Pervin The University of Texas at Dallas Richardson, Texas.
Chapter 5. Operations on Multiple R. V.'s 1 Chapter 5. Operations on Multiple Random Variables 0. Introduction 1. Expected Value of a Function of Random.
Chapter 4 Joint Distribution & Function of rV. Joint Discrete Distribution Definition.
Sep 20, 2005CS477: Analog and Digital Communications1 Random variables, Random processes Analog and Digital Communications Autumn
Statistical Theory; Why is the Gaussian Distribution so popular? Rob Nicholls MRC LMB Statistics Course 2014.
Chapter 21 Random Variables Discrete: Bernoulli, Binomial, Geometric, Poisson Continuous: Uniform, Exponential, Gamma, Normal Expectation & Variance, Joint.
The Erik Jonsson School of Engineering and Computer Science Chapter 1 pp William J. Pervin The University of Texas at Dallas Richardson, Texas
ELEC 303, Koushanfar, Fall’09 ELEC 303 – Random Signals Lecture 11 – Derived distributions, covariance, correlation and convolution Dr. Farinaz Koushanfar.
Functions of Random Variables. Methods for determining the distribution of functions of Random Variables 1.Distribution function method 2.Moment generating.
IRDM WS Chapter 2: Basics from Probability Theory and Statistics 2.1 Probability Theory Events, Probabilities, Random Variables, Distributions,
Winter 2006EE384x1 Review of Probability Theory Review Session 1 EE384X.
Further distributions
ELEC 303 – Random Signals Lecture 13 – Transforms Dr. Farinaz Koushanfar ECE Dept., Rice University Oct 15, 2009.
Lecture 12 Vector of Random Variables
PROBABILITY AND STATISTICS FOR ENGINEERING Hossein Sameti Department of Computer Engineering Sharif University of Technology Two Functions of Two Random.
Functions of Random Variables. Methods for determining the distribution of functions of Random Variables 1.Distribution function method 2.Moment generating.
Use of moment generating functions 1.Using the moment generating functions of X, Y, Z, …determine the moment generating function of W = h(X, Y, Z, …).
The Mean of a Discrete RV The mean of a RV is the average value the RV takes over the long-run. –The mean of a RV is analogous to the mean of a large population.
Chapter 5.6 From DeGroot & Schervish. Uniform Distribution.
1 Two Functions of Two Random Variables In the spirit of the previous lecture, let us look at an immediate generalization: Suppose X and Y are two random.
The Erik Jonsson School of Engineering and Computer Science Chapter 3 pp William J. Pervin The University of Texas at Dallas Richardson, Texas.
Lecture 11 Pairs and Vector of Random Variables Last Time Pairs of R.Vs. Marginal PMF (Cont.) Joint PDF Marginal PDF Functions of Two R.Vs Expected Values.
Probability Refresher. Events Events as possible outcomes of an experiment Events define the sample space (discrete or continuous) – Single throw of a.
7 sum of RVs. 7-1: variance of Z Find the variance of Z = X+Y by using Var(X), Var(Y), and Cov(X,Y)
EE 5345 Multiple Random Variables
IE 300, Fall 2012 Richard Sowers IESE. 8/30/2012 Goals: Rules of Probability Counting Equally likely Some examples.
Chapter 5a:Functions of Random Variables Yang Zhenlin.
Continuous Random Variable (1) Section Continuous Random Variable What is the probability that X is equal to x?
Distributions of Functions of Random Variables November 18, 2015
Probability and Moment Approximations using Limit Theorems.
Section 5 – Expectation and Other Distribution Parameters.
Joint Moments and Joint Characteristic Functions.
EEE APPENDIX B Transformation of RV Huseyin Bilgekul EEE 461 Communication Systems II Department of Electrical and Electronic Engineering Eastern.
Lecture 15 Parameter Estimation Using Sample Mean Last Time Sums of R. V.s Moment Generating Functions MGF of the Sum of Indep. R.Vs Sample Mean (7.1)
The Erik Jonsson School of Engineering and Computer Science Chapter 4 pp William J. Pervin The University of Texas at Dallas Richardson, Texas.
Lecture 5,6,7: Random variables and signals Aliazam Abbasfar.
Week 111 Some facts about Power Series Consider the power series with non-negative coefficients a k. If converges for any positive value of t, say for.
STA347 - week 91 Random Vectors and Matrices A random vector is a vector whose elements are random variables. The collective behavior of a p x 1 random.
ELEC 303, Koushanfar, Fall’09 ELEC 303 – Random Signals Lecture 9 – Continuous Random Variables: Joint PDFs, Conditioning, Continuous Bayes Farinaz Koushanfar.
ELEC 303, Koushanfar, Fall’09 ELEC 303 – Random Signals Lecture 8 – Continuous Random Variables: PDF and CDFs Farinaz Koushanfar ECE Dept., Rice University.
Geology 6600/7600 Signal Analysis 04 Sep 2014 © A.R. Lowry 2015 Last time: Signal Analysis is a set of tools used to extract information from sequences.
Erik Jonsson School of Engineering and Computer Science FEARLESS Engineeringwww.utdallas.edu/~pervin ENGR 3300 – 505 Advanced Engineering Mathematics
Sums of Random Variables and Long-Term Averages Sums of R.V. ‘s S n = X 1 + X X n of course.
Random Variables By: 1.
Cumulative distribution functions and expected values
PRODUCT MOMENTS OF BIVARIATE RANDOM VARIABLES
Useful Discrete Random Variables
5.6 The Central Limit Theorem
The University of Texas at Dallas
APPENDIX B Multivariate Statistics
Chapter 3 : Random Variables
Chap 11 Sums of Independent Random Variables and Limit Theorem Ghahramani 3rd edition 2019/5/16.
Berlin Chen Department of Computer Science & Information Engineering
Introduction to Probability: Solutions for Quizzes 4 and 5
Berlin Chen Department of Computer Science & Information Engineering
EE255/CPS226 Expected Value and Higher Moments
Presentation transcript:

The Erik Jonsson School of Engineering and Computer Science Chapter 6 pp William J. Pervin The University of Texas at Dallas Richardson, Texas 75083

The Erik Jonsson School of Engineering and Computer Science Chapter 6 Sums of Random Variables

The Erik Jonsson School of Engineering and Computer Science Chapter Expected Values of Sums: E[ΣX i ] = ΣE[X i ] Var[ΣX i ] = ΣVar[X i ] + ΣΣ (i≠j) Cov[X i,X j ]

The Erik Jonsson School of Engineering and Computer Science Chapter PDF of the Sum of Two RVs: The PDF of W = X + Y is: f W (w) = ∫ f X,Y (x,w-x)dx = ∫ f X,Y (w-y,y)dy

The Erik Jonsson School of Engineering and Computer Science Chapter 6 If X and Y are independent RVs, then the PDF of W = X + Y is f W (w) = ∫f X (w-y)f Y (y)dy = ∫f X (x)f Y (w-x)dx = f X * f Y : the convolution

The Erik Jonsson School of Engineering and Computer Science Chapter Moment Generating Functions: The MGF Φ X of a RV X is the transform Continuous: Φ X (s) = ∫e sx f X (x)dx Discrete: Φ X (s) = Σe sx i f X (x i )

The Erik Jonsson School of Engineering and Computer Science Chapter 6 The sum of independent Poisson/Gaussian RVs is a Poisson/Gaussian RV.

The Erik Jonsson School of Engineering and Computer Science Chapter Central Limit Theorem: The CDF of the sum of any number n of iid RVs approaches the Gaussian CDF with the same mean and variance as n increases!