Random Variables, Expectation, Distributions


 Roderick Lionel Hodge
 1 years ago
 Views:
Transcription
1 Random Variables, Expectation, Distributions CS 5960/6960: Nonparametric Methods Tom Fletcher January 21, 2009
2 Review
3 Random Variables Definition A random variable is a function defined on a probability space. In other words, if (Ω, F, P) is a probability space, then a random variable is a function X : Ω V for some set V. Note: A random variable is neither random nor a variable. We will deal with integervalued (V = Z) or realvalued (V = R) random variables. Technically, random variables are measurable functions.
4 Dice Example Let (Ω, F, P) be the probability space for rolling a pair of dice, and let X : Ω Z be the random variable that gives the sum of the numbers on the two dice. So, X[(1, 2)] = 3, X[(4, 4)] = 8, X[(6, 5)] = 11
5 Even Simpler Example Most of the time the random variable X will just be the identity function. For example, if the sample space is the real line, Ω = R, the identity function is a random variable. X : R R, X(s) = s
6 Defining Events via Random Variables Setting a realvalued random variable to a value or range of values defines an event. [X = x] = {s Ω : X(s) = x} [X < x] = {s Ω : X(s) < x} [a < X < b] = {s Ω : a < X(s) < b}
7 Cumulative Distribution Functions Definition Let X be a realvalued random variable on the probability space (Ω, F, P). Then the cumulative distribution function (cdf) of X is defined as F X (x) = P(X < x)
8 Properties of CDFs Let X be a realvalued random variable. Then F X has the following properties: 1. F X is monotonic increasing. 2. F X is rightcontinuous, that is, lim F X(x + ɛ) = F X (x), for all x R. ɛ lim x F X(x) = 0 and lim x F X (x) = 1.
9 Probability Mass Functions (Discrete) Definition The probability mass function (pmf) for a discrete realvalued random variable X, denoted f X, is defined as f X (x) = P(X = x). The cdf can be defined in terms of the pmf as F X (x) = P(X x) = k x f X (k).
10 Probability Density Functions (Continuous) Definition The probability density function (pdf) for a continuous realvalued random variable X, denoted f X, is defined as when this derivative exists. f X (x) = d dx F X(x), The cdf can be defined in terms of the pdf as F X (x) = P(X x) = x f X (t)dt.
11 Example: Uniform Distribution X Unif(0, 1) X is uniformly distributed between 0 and 1. f X (x) = { 1 0 x 1 0 otherwise 0 x < 0 F X (x) = x 0 x 1 1 x > 1
12 Joint Distributions Recall that given two events A, B, we can talk about the intersection of the two events A B and the probability P(A B) of both events happening. Given two random variables, X, Y, we can also talk about the intersection of the events these variables define. The distribution defined this way is called the joint distribution: F X,Y (x, y) = P(X x; Y y) = y x f X,Y (s, t)dsdt.
13 Marginal Distributions Definition Given a joint probability density f X,Y, the marginal densities of X and Y are given by f X (x) = f Y (y) = f X,Y (x, y)dy, f X,Y (x, y)dx. and
14 Conditional Densities Definition If X, Y are random variables with joint density f X,Y, then the conditional density of X given Y = y is f X Y=y (x) = f X,Y(x, y). f Y (y)
15 Independent Random Variables Definition Two random variables X, Y are called independent if f X,Y (x, y) = f X (x)f Y (y). If we integrate (or sum) both sides, we see this is equivalent to F X,Y (x, y) = F X (x)f Y (y).
16 Expectation Definition The expectation of a random variable X is E[X] = x f X (x)dx. This is the mean value of X, also denoted µ X = E[X].
17 Linearity of Expectation If X and Y are random variables, and a, b R, then E[aX + by] = ae[x] + be[y]. This extends the several random variables X i and constants a i : [ N ] N E a i X i = a i E[X i ]. i=1 i=1
18 Variance Definition The variance of a random variable X is defined as Var(X) = E[(X µ X ) 2 ]. This formula is equivalent to Var(X) = E[X 2 ] µ 2 X. The variance is a measure of the spread of the distribution. The standard deviation is the sqrt of variance: σ X = Var(X).
19 Example: Normal Distribution X N(µ, σ) X is normally distributed with mean µ and standard deviation σ. f X (x) = 1 2πσ exp F X (x) = x ( ) (x µ)2 2σ 2 f X (t)dt
20 Expectation of the Product of Two RVs We can take the expected value of the product of two random variables, X and Y: E[XY] = xy f X,Y (x, y)dxdy.
21 Covariance Definition The covariance of two random variables X and Y is Cov(X, Y) = E[(X µ X )(Y µ Y )] = E[XY] µ X µ Y. This is a measure of how much the variables X and Y change together. We ll also write σ XY = Cov(X, Y).
22 Correlation Definition The correlation of two random variables X and Y is ρ(x, Y) = σ XY σ X σ Y, or [( ) ( X µx Y µy ρ(x, Y) = E σ X σ Y )]. Correlation normalizes the covariance between [ 1, 1].
23 Independent RVs are Uncorrelated If X and Y are two independent RVs, then E[XY] = = = x f X (x)dx xy f X,Y (x, y)dxdy xy f X (x)f Y (y)dxdy = E[X]E[Y] = µ X µ Y So, σ XY = E[XY] µ X µ Y = 0. y f Y (y)dy
24 More on Indepdence and Correlation Warning: Independence implies uncorrelation, but uncorrelated variables are not necessarily independent!
Jointly Distributed Random Variables
Jointly Distributed Random Variables COMP 245 STATISTICS Dr N A Heard Contents 1 Jointly Distributed Random Variables 1 1.1 Definition......................................... 1 1.2 Joint cdfs..........................................
More informationJoint Probability Distributions and Random Samples (Devore Chapter Five)
Joint Probability Distributions and Random Samples (Devore Chapter Five) 101634501 Probability and Statistics for Engineers Winter 20102011 Contents 1 Joint Probability Distributions 1 1.1 Two Discrete
More informationTopic 4: Multivariate random variables. Multiple random variables
Topic 4: Multivariate random variables Joint, marginal, and conditional pmf Joint, marginal, and conditional pdf and cdf Independence Expectation, covariance, correlation Conditional expectation Two jointly
More informationST 371 (VIII): Theory of Joint Distributions
ST 371 (VIII): Theory of Joint Distributions So far we have focused on probability distributions for single random variables. However, we are often interested in probability statements concerning two or
More informationCovariance and Correlation. Consider the joint probability distribution f XY (x, y).
Chapter 5: JOINT PROBABILITY DISTRIBUTIONS Part 2: Section 52 Covariance and Correlation Consider the joint probability distribution f XY (x, y). Is there a relationship between X and Y? If so, what kind?
More informationJoint Distributions. Tieming Ji. Fall 2012
Joint Distributions Tieming Ji Fall 2012 1 / 33 X : univariate random variable. (X, Y ): bivariate random variable. In this chapter, we are going to study the distributions of bivariate random variables
More informationSTAT 430/510 Probability Lecture 14: Joint Probability Distribution, Continuous Case
STAT 430/510 Probability Lecture 14: Joint Probability Distribution, Continuous Case Pengyuan (Penelope) Wang June 20, 2011 Joint density function of continuous Random Variable When X and Y are two continuous
More informationJoint Probability Distributions and Random Samples. Week 5, 2011 Stat 4570/5570 Material from Devore s book (Ed 8), and Cengage
5 Joint Probability Distributions and Random Samples Week 5, 2011 Stat 4570/5570 Material from Devore s book (Ed 8), and Cengage Two Discrete Random Variables The probability mass function (pmf) of a single
More information4. Joint Distributions of Two Random Variables
4. Joint Distributions of Two Random Variables 4.1 Joint Distributions of Two Discrete Random Variables Suppose the discrete random variables X and Y have supports S X and S Y, respectively. The joint
More informationBivariate Distributions
Chapter 4 Bivariate Distributions 4.1 Distributions of Two Random Variables In many practical cases it is desirable to take more than one measurement of a random observation: (brief examples) 1. What is
More information3 Multiple Discrete Random Variables
3 Multiple Discrete Random Variables 3.1 Joint densities Suppose we have a probability space (Ω, F,P) and now we have two discrete random variables X and Y on it. They have probability mass functions f
More informationStatistiek (WISB361)
Statistiek (WISB361) Final exam June 29, 2015 Schrijf uw naam op elk in te leveren vel. Schrijf ook uw studentnummer op blad 1. The maximum number of points is 100. Points distribution: 23 20 20 20 17
More informationChapter 4. Multivariate Distributions
1 Chapter 4. Multivariate Distributions Joint p.m.f. (p.d.f.) Independent Random Variables Covariance and Correlation Coefficient Expectation and Covariance Matrix Multivariate (Normal) Distributions Matlab
More informationL10: Probability, statistics, and estimation theory
L10: Probability, statistics, and estimation theory Review of probability theory Bayes theorem Statistics and the Normal distribution Least Squares Error estimation Maximum Likelihood estimation Bayesian
More informationLecture Notes 1. Brief Review of Basic Probability
Probability Review Lecture Notes Brief Review of Basic Probability I assume you know basic probability. Chapters 3 are a review. I will assume you have read and understood Chapters 3. Here is a very
More informationLecture 6: Discrete & Continuous Probability and Random Variables
Lecture 6: Discrete & Continuous Probability and Random Variables D. Alex Hughes Math Camp September 17, 2015 D. Alex Hughes (Math Camp) Lecture 6: Discrete & Continuous Probability and Random September
More informationChapters 5. Multivariate Probability Distributions
Chapters 5. Multivariate Probability Distributions Random vectors are collection of random variables defined on the same sample space. Whenever a collection of random variables are mentioned, they are
More informationLesson 5 Chapter 4: Jointly Distributed Random Variables
Lesson 5 Chapter 4: Jointly Distributed Random Variables Department of Statistics The Pennsylvania State University 1 Marginal and Conditional Probability Mass Functions The Regression Function Independence
More informationChapter 4  Lecture 1 Probability Density Functions and Cumul. Distribution Functions
Chapter 4  Lecture 1 Probability Density Functions and Cumulative Distribution Functions October 21st, 2009 Review Probability distribution function Useful results Relationship between the pdf and the
More informationECE302 Spring 2006 HW7 Solutions March 11, 2006 1
ECE32 Spring 26 HW7 Solutions March, 26 Solutions to HW7 Note: Most of these solutions were generated by R. D. Yates and D. J. Goodman, the authors of our textbook. I have added comments in italics where
More informationMath 431 An Introduction to Probability. Final Exam Solutions
Math 43 An Introduction to Probability Final Eam Solutions. A continuous random variable X has cdf a for 0, F () = for 0 <
More informationFor a partition B 1,..., B n, where B i B j = for i. A = (A B 1 ) (A B 2 ),..., (A B n ) and thus. P (A) = P (A B i ) = P (A B i )P (B i )
Probability Review 15.075 Cynthia Rudin A probability space, defined by Kolmogorov (19031987) consists of: A set of outcomes S, e.g., for the roll of a die, S = {1, 2, 3, 4, 5, 6}, 1 1 2 1 6 for the roll
More informationP (x) 0. Discrete random variables Expected value. The expected value, mean or average of a random variable x is: xp (x) = v i P (v i )
Discrete random variables Probability mass function Given a discrete random variable X taking values in X = {v 1,..., v m }, its probability mass function P : X [0, 1] is defined as: P (v i ) = Pr[X =
More informationIntroduction to Probability
Introduction to Probability EE 179, Lecture 15, Handout #24 Probability theory gives a mathematical characterization for experiments with random outcomes. coin toss life of lightbulb binary data sequence
More informationSections 2.11 and 5.8
Sections 211 and 58 Timothy Hanson Department of Statistics, University of South Carolina Stat 704: Data Analysis I 1/25 Gesell data Let X be the age in in months a child speaks his/her first word and
More informationWorked examples Multiple Random Variables
Worked eamples Multiple Random Variables Eample Let X and Y be random variables that take on values from the set,, } (a) Find a joint probability mass assignment for which X and Y are independent, and
More informationCovariance and Correlation
Covariance and Correlation ( c Robert J. Serfling Not for reproduction or distribution) We have seen how to summarize a databased relative frequency distribution by measures of location and spread, such
More informationMULTIVARIATE PROBABILITY DISTRIBUTIONS
MULTIVARIATE PROBABILITY DISTRIBUTIONS. PRELIMINARIES.. Example. Consider an experiment that consists of tossing a die and a coin at the same time. We can consider a number of random variables defined
More informationExamination 110 Probability and Statistics Examination
Examination 0 Probability and Statistics Examination Sample Examination Questions The Probability and Statistics Examination consists of 5 multiplechoice test questions. The test is a threehour examination
More informationSection 6.1 Joint Distribution Functions
Section 6.1 Joint Distribution Functions We often care about more than one random variable at a time. DEFINITION: For any two random variables X and Y the joint cumulative probability distribution function
More informationJoint Exam 1/P Sample Exam 1
Joint Exam 1/P Sample Exam 1 Take this practice exam under strict exam conditions: Set a timer for 3 hours; Do not stop the timer for restroom breaks; Do not look at your notes. If you believe a question
More informationST 371 (IV): Discrete Random Variables
ST 371 (IV): Discrete Random Variables 1 Random Variables A random variable (rv) is a function that is defined on the sample space of the experiment and that assigns a numerical variable to each possible
More informationNotes 11 Autumn 2005
MAS 08 Probabilit I Notes Autumn 005 Two discrete random variables If X and Y are discrete random variables defined on the same sample space, then events such as X = and Y = are well defined. The joint
More informationDefinition: Suppose that two random variables, either continuous or discrete, X and Y have joint density
HW MATH 461/561 Lecture Notes 15 1 Definition: Suppose that two random variables, either continuous or discrete, X and Y have joint density and marginal densities f(x, y), (x, y) Λ X,Y f X (x), x Λ X,
More information5. Continuous Random Variables
5. Continuous Random Variables Continuous random variables can take any value in an interval. They are used to model physical characteristics such as time, length, position, etc. Examples (i) Let X be
More informationWhat is Statistics? Lecture 1. Introduction and probability review. Idea of parametric inference
0. 1. Introduction and probability review 1.1. What is Statistics? What is Statistics? Lecture 1. Introduction and probability review There are many definitions: I will use A set of principle and procedures
More informationRandom variables P(X = 3) = P(X = 3) = 1 8, P(X = 1) = P(X = 1) = 3 8.
Random variables Remark on Notations 1. When X is a number chosen uniformly from a data set, What I call P(X = k) is called Freq[k, X] in the courseware. 2. When X is a random variable, what I call F ()
More informationRandom Variables. Chapter 2. Random Variables 1
Random Variables Chapter 2 Random Variables 1 Roulette and Random Variables A Roulette wheel has 38 pockets. 18 of them are red and 18 are black; these are numbered from 1 to 36. The two remaining pockets
More informationM2S1 Lecture Notes. G. A. Young http://www2.imperial.ac.uk/ ayoung
M2S1 Lecture Notes G. A. Young http://www2.imperial.ac.uk/ ayoung September 2011 ii Contents 1 DEFINITIONS, TERMINOLOGY, NOTATION 1 1.1 EVENTS AND THE SAMPLE SPACE......................... 1 1.1.1 OPERATIONS
More information6. Jointly Distributed Random Variables
6. Jointly Distributed Random Variables We are often interested in the relationship between two or more random variables. Example: A randomly chosen person may be a smoker and/or may get cancer. Definition.
More informationTopic 8 The Expected Value
Topic 8 The Expected Value Functions of Random Variables 1 / 12 Outline Names for Eg(X ) Variance and Standard Deviation Independence Covariance and Correlation 2 / 12 Names for Eg(X ) If g(x) = x, then
More informationSTA 256: Statistics and Probability I
Al Nosedal. University of Toronto. Fall 2014 1 2 3 4 5 My momma always said: Life was like a box of chocolates. You never know what you re gonna get. Forrest Gump. Experiment, outcome, sample space, and
More informationSummary of Formulas and Concepts. Descriptive Statistics (Ch. 14)
Summary of Formulas and Concepts Descriptive Statistics (Ch. 14) Definitions Population: The complete set of numerical information on a particular quantity in which an investigator is interested. We assume
More informationJoint Distribution and Correlation
Joint Distribution and Correlation Michael Ash Lecture 3 Reminder: Start working on the Problem Set Mean and Variance of Linear Functions of an R.V. Linear Function of an R.V. Y = a + bx What are the properties
More informationEstimation with Minimum Mean Square Error
C H A P T E R 8 Estimation with Minimum Mean Square Error INTRODUCTION A recurring theme in this text and in much of communication, control and signal processing is that of making systematic estimates,
More informationJoint distributions Math 217 Probability and Statistics Prof. D. Joyce, Fall 2014
Joint distributions Math 17 Probability and Statistics Prof. D. Joyce, Fall 14 Today we ll look at joint random variables and joint distributions in detail. Product distributions. If Ω 1 and Ω are sample
More informationThe sample space for a pair of die rolls is the set. The sample space for a random number between 0 and 1 is the interval [0, 1].
Probability Theory Probability Spaces and Events Consider a random experiment with several possible outcomes. For example, we might roll a pair of dice, flip a coin three times, or choose a random real
More informationStat 704 Data Analysis I Probability Review
1 / 30 Stat 704 Data Analysis I Probability Review Timothy Hanson Department of Statistics, University of South Carolina Course information 2 / 30 Logistics: Tuesday/Thursday 11:40am to 12:55pm in LeConte
More informationSYSM 6304: Risk and Decision Analysis Lecture 3 Monte Carlo Simulation
SYSM 6304: Risk and Decision Analysis Lecture 3 Monte Carlo Simulation M. Vidyasagar Cecil & Ida Green Chair The University of Texas at Dallas Email: M.Vidyasagar@utdallas.edu September 19, 2015 Outline
More informationMathematical Expectation
Mathematical Expectation Properties of Mathematical Expectation I The concept of mathematical expectation arose in connection with games of chance. In its simplest form, mathematical expectation is the
More informationUniversity of California, Los Angeles Department of Statistics. Random variables
University of California, Los Angeles Department of Statistics Statistics Instructor: Nicolas Christou Random variables Discrete random variables. Continuous random variables. Discrete random variables.
More informationOverview of Monte Carlo Simulation, Probability Review and Introduction to Matlab
Monte Carlo Simulation: IEOR E4703 Fall 2004 c 2004 by Martin Haugh Overview of Monte Carlo Simulation, Probability Review and Introduction to Matlab 1 Overview of Monte Carlo Simulation 1.1 Why use simulation?
More informationMath 370, Spring 2008 Prof. A.J. Hildebrand. Practice Test 2 Solutions
Math 370, Spring 008 Prof. A.J. Hildebrand Practice Test Solutions About this test. This is a practice test made up of a random collection of 5 problems from past Course /P actuarial exams. Most of the
More informationAnNajah National University Faculty of Engineering Industrial Engineering Department. Course : Quantitative Methods (65211)
AnNajah National University Faculty of Engineering Industrial Engineering Department Course : Quantitative Methods (65211) Instructor: Eng. Tamer Haddad 2 nd Semester 2009/2010 Chapter 5 Example: Joint
More informationSection 5.1 Continuous Random Variables: Introduction
Section 5. Continuous Random Variables: Introduction Not all random variables are discrete. For example:. Waiting times for anything (train, arrival of customer, production of mrna molecule from gene,
More informationFeb 28 Homework Solutions Math 151, Winter 2012. Chapter 6 Problems (pages 287291)
Feb 8 Homework Solutions Math 5, Winter Chapter 6 Problems (pages 879) Problem 6 bin of 5 transistors is known to contain that are defective. The transistors are to be tested, one at a time, until the
More informationCorrelation in Random Variables
Correlation in Random Variables Lecture 11 Spring 2002 Correlation in Random Variables Suppose that an experiment produces two random variables, X and Y. What can we say about the relationship between
More informationWe have discussed the notion of probabilistic dependence above and indicated that dependence is
1 CHAPTER 7 Online Supplement Covariance and Correlation for Measuring Dependence We have discussed the notion of probabilistic dependence above and indicated that dependence is defined in terms of conditional
More informationRecitation 4. 24xy for 0 < x < 1, 0 < y < 1, x + y < 1 0 elsewhere
Recitation. Exercise 3.5: If the joint probability density of X and Y is given by xy for < x
More informationExamples: Joint Densities and Joint Mass Functions Example 1: X and Y are jointly continuous with joint pdf
AMS 3 Joe Mitchell Eamples: Joint Densities and Joint Mass Functions Eample : X and Y are jointl continuous with joint pdf f(,) { c 2 + 3 if, 2, otherwise. (a). Find c. (b). Find P(X + Y ). (c). Find marginal
More informationExercises with solutions (1)
Exercises with solutions (). Investigate the relationship between independence and correlation. (a) Two random variables X and Y are said to be correlated if and only if their covariance C XY is not equal
More informationSome probability and statistics
Appendix A Some probability and statistics A Probabilities, random variables and their distribution We summarize a few of the basic concepts of random variables, usually denoted by capital letters, X,Y,
More informationby Dimitri P. Bertsekas and John N. Tsitsiklis SECTION 3.1. Continuous Random Variables and PDFs
INTRODUCTION TO PROBABILITY by Dimitri P. Bertsekas and John N. Tsitsiklis CHAPTER 3: ADDITIONAL PROBLEMS SECTION 3.1. Continuous Random Variables and PDFs Problem 1. The runnerup in a road race is given
More informationMTH135/STA104: Probability
MTH135/STA14: Probability Homework # 8 Due: Tuesday, Nov 8, 5 Prof Robert Wolpert 1 Define a function f(x, y) on the plane R by { 1/x < y < x < 1 f(x, y) = other x, y a) Show that f(x, y) is a joint probability
More informationThe Big 50 Revision Guidelines for S1
The Big 50 Revision Guidelines for S1 If you can understand all of these you ll do very well 1. Know what is meant by a statistical model and the Modelling cycle of continuous refinement 2. Understand
More informationCalculate the holding period return for this investment. It is approximately
1. An investor purchases 100 shares of XYZ at the beginning of the year for $35. The stock pays a cash dividend of $3 per share. The price of the stock at the time of the dividend is $30. The dividend
More informationChange of Continuous Random Variable
Change of Continuous Random Variable All you are responsible for from this lecture is how to implement the Engineer s Way (see page 4) to compute how the probability density function changes when we make
More informationMath 432 HW 2.5 Solutions
Math 432 HW 2.5 Solutions Assigned: 110, 12, 13, and 14. Selected for Grading: 1 (for five points), 6 (also for five), 9, 12 Solutions: 1. (2y 3 + 2y 2 ) dx + (3y 2 x + 2xy) dy = 0. M/ y = 6y 2 + 4y N/
More informationChap 3 : Two Random Variables
Chap 3 : Two Random Variables Chap 3.1: Distribution Functions of Two RVs In many experiments, the observations are expressible not as a single quantity, but as a family of quantities. For example to record
More informationData Modeling & Analysis Techniques. Probability & Statistics. Manfred Huber 2011 1
Data Modeling & Analysis Techniques Probability & Statistics Manfred Huber 2011 1 Probability and Statistics Probability and statistics are often used interchangeably but are different, related fields
More informationMT426 Notebook 3 Fall 2012 prepared by Professor Jenny Baglivo. 3 MT426 Notebook 3 3. 3.1 Definitions... 3. 3.2 Joint Discrete Distributions...
MT426 Notebook 3 Fall 2012 prepared by Professor Jenny Baglivo c Copyright 20042012 by Jenny A. Baglivo. All Rights Reserved. Contents 3 MT426 Notebook 3 3 3.1 Definitions............................................
More informationGenerating Random Numbers Variance Reduction QuasiMonte Carlo. Simulation Methods. Leonid Kogan. MIT, Sloan. 15.450, Fall 2010
Simulation Methods Leonid Kogan MIT, Sloan 15.450, Fall 2010 c Leonid Kogan ( MIT, Sloan ) Simulation Methods 15.450, Fall 2010 1 / 35 Outline 1 Generating Random Numbers 2 Variance Reduction 3 QuasiMonte
More informationFundamentals of Probability and Statistics for Reliability. analysis. Chapter 2
Chapter 2 Fundamentals of Probability and Statistics for Reliability Analysis Assessment of the reliability of a hydrosystems infrastructural system or its components involves the use of probability and
More informationP(a X b) = f X (x)dx. A p.d.f. must integrate to one: f X (x)dx = 1. Z b
Continuous Random Variables The probability that a continuous random variable, X, has a value between a and b is computed by integrating its probability density function (p.d.f.) over the interval [a,b]:
More informationChapter 5: Joint Probability Distributions. Chapter Learning Objectives. The Joint Probability Distribution for a Pair of Discrete Random
Chapter 5: Joint Probability Distributions 51 Two or More Random Variables 51.1 Joint Probability Distributions 51.2 Marginal Probability Distributions 51.3 Conditional Probability Distributions 51.4
More informationLecture 3: Continuous distributions, expected value & mean, variance, the normal distribution
Lecture 3: Continuous distributions, expected value & mean, variance, the normal distribution 8 October 2007 In this lecture we ll learn the following: 1. how continuous probability distributions differ
More informationExample. A casino offers the following bets (the fairest bets in the casino!) 1 You get $0 (i.e., you can walk away)
: Three bets Math 45 Introduction to Probability Lecture 5 Kenneth Harris aharri@umich.edu Department of Mathematics University of Michigan February, 009. A casino offers the following bets (the fairest
More informationMAS108 Probability I
1 QUEEN MARY UNIVERSITY OF LONDON 2:30 pm, Thursday 3 May, 2007 Duration: 2 hours MAS108 Probability I Do not start reading the question paper until you are instructed to by the invigilators. The paper
More informationTransformations and Expectations of random variables
Transformations and Epectations of random variables X F X (): a random variable X distributed with CDF F X. Any function Y = g(x) is also a random variable. If both X, and Y are continuous random variables,
More informationProbability for Estimation (review)
Probability for Estimation (review) In general, we want to develop an estimator for systems of the form: x = f x, u + η(t); y = h x + ω(t); ggggg y, ffff x We will primarily focus on discrete time linear
More informationMathematical Background
Appendix A Mathematical Background A.1 Joint, Marginal and Conditional Probability Let the n (discrete or continuous) random variables y 1,..., y n have a joint joint probability probability p(y 1,...,
More informationA Tutorial on Probability Theory
Paola Sebastiani Department of Mathematics and Statistics University of Massachusetts at Amherst Corresponding Author: Paola Sebastiani. Department of Mathematics and Statistics, University of Massachusetts,
More informationNotes on Continuous Random Variables
Notes on Continuous Random Variables Continuous random variables are random quantities that are measured on a continuous scale. They can usually take on any value over some interval, which distinguishes
More informationThe Bivariate Normal Distribution
The Bivariate Normal Distribution This is Section 4.7 of the st edition (2002) of the book Introduction to Probability, by D. P. Bertsekas and J. N. Tsitsiklis. The material in this section was not included
More informationStatistics 100 Binomial and Normal Random Variables
Statistics 100 Binomial and Normal Random Variables Three different random variables with common characteristics: 1. Flip a fair coin 10 times. Let X = number of heads out of 10 flips. 2. Poll a random
More informationSolutions to Exam in Speech Signal Processing EN2300
Solutions to Exam in Speech Signal Processing EN23 Date: Thursday, Dec 2, 8: 3: Place: Allowed: Grades: Language: Solutions: Q34, Q36 Beta Math Handbook (or corresponding), calculator with empty memory.
More informationVariances and covariances
Chapter 4 Variances and covariances 4.1 Overview The expected value of a random variable gives a crude measure for the center of location of the distribution of that random variable. For instance, if the
More informationChapter 4 Lecture Notes
Chapter 4 Lecture Notes Random Variables October 27, 2015 1 Section 4.1 Random Variables A random variable is typically a realvalued function defined on the sample space of some experiment. For instance,
More informationThe Scalar Algebra of Means, Covariances, and Correlations
3 The Scalar Algebra of Means, Covariances, and Correlations In this chapter, we review the definitions of some key statistical concepts: means, covariances, and correlations. We show how the means, variances,
More informationStatistics  Written Examination MEC Students  BOVISA
Statistics  Written Examination MEC Students  BOVISA Prof.ssa A. Guglielmi 26.0.2 All rights reserved. Legal action will be taken against infringement. Reproduction is prohibited without prior consent.
More informationMeasurements of central tendency express whether the numbers tend to be high or low. The most common of these are:
A PRIMER IN PROBABILITY This handout is intended to refresh you on the elements of probability and statistics that are relevant for econometric analysis. In order to help you prioritize the information
More informationSolution to HW  1. Problem 1. [Points = 3] In September, Chapel Hill s daily high temperature has a mean
Problem 1. [Points = 3] In September, Chapel Hill s daily high temperature has a mean of 81 degree F and a standard deviation of 10 degree F. What is the mean, standard deviation and variance in terms
More information6.041/6.431 Spring 2008 Quiz 2 Wednesday, April 16, 7:309:30 PM. SOLUTIONS
6.4/6.43 Spring 28 Quiz 2 Wednesday, April 6, 7:39:3 PM. SOLUTIONS Name: Recitation Instructor: TA: 6.4/6.43: Question Part Score Out of 3 all 36 2 a 4 b 5 c 5 d 8 e 5 f 6 3 a 4 b 6 c 6 d 6 e 6 Total
More informationJoint Probability Distributions and Random Samples
STAT5 Sprig 204 Lecture Notes Chapter 5 February, 204 Joit Probability Distributios ad Radom Samples 5. Joitly Distributed Radom Variables Chapter Overview Joitly distributed rv Joit mass fuctio, margial
More informationSTAT 3502. x 0 < x < 1
Solution  Assignment # STAT 350 Total mark=100 1. A large industrial firm purchases several new word processors at the end of each year, the exact number depending on the frequency of repairs in the previous
More informationLecture 9: Introduction to Pattern Analysis
Lecture 9: Introduction to Pattern Analysis g Features, patterns and classifiers g Components of a PR system g An example g Probability definitions g Bayes Theorem g Gaussian densities Features, patterns
More informationMath 370, Actuarial Problemsolving Spring 2008 A.J. Hildebrand. Practice Test, 1/28/2008 (with solutions)
Math 370, Actuarial Problemsolving Spring 008 A.J. Hildebrand Practice Test, 1/8/008 (with solutions) About this test. This is a practice test made up of a random collection of 0 problems from past Course
More informationBNG 202 Biomechanics Lab. Descriptive statistics and probability distributions I
BNG 202 Biomechanics Lab Descriptive statistics and probability distributions I Overview The overall goal of this short course in statistics is to provide an introduction to descriptive and inferential
More informationTRANSFORMATIONS OF RANDOM VARIABLES
TRANSFORMATIONS OF RANDOM VARIABLES 1. INTRODUCTION 1.1. Definition. We are often interested in the probability distributions or densities of functions of one or more random variables. Suppose we have
More informationAggregate Loss Models
Aggregate Loss Models Chapter 9 Stat 477  Loss Models Chapter 9 (Stat 477) Aggregate Loss Models Brian Hartman  BYU 1 / 22 Objectives Objectives Individual risk model Collective risk model Computing
More information