random variables & probability distributions

Upload: yashar2500

Post on 04-Nov-2015

53 views

Category:

Documents


0 download

DESCRIPTION

Random Variables & Probability Distributions

TRANSCRIPT

  • TUM School of Management Production and Supply Chain Management Prof Martin Grunow Technische Universitt Mnchen

    Quality Engineering & Management

    Session 2.2: Random Variables & Probability Distributions

    Dr. Holly Ott Production and Supply Chain Management

    Chair: Prof. Martin Grunow TUM School of Management

    Holly Ott Quality Engineering & Management Module 2.2 1

  • TUM School of Management Production and Supply Chain Management Prof Martin Grunow Technische Universitt Mnchen

    Learning Objectives

    List the properties and types of random variables. Understand the meaning of probability distribution functions for

    discrete and continuous variables.

    Describe the cumulative distribution function. Define the mean and variance for a probability distribution

    functions.

    Review several important distribution functions.

    Holly Ott Quality Engineering & Management Module 2.2 2

  • TUM School of Management Production and Supply Chain Management Prof Martin Grunow Technische Universitt Mnchen

    Random Variables

    A random variable is a variable, which assumes for its values the outcomes of a random experiment.

    A random variable assumes only real numbers.

    The set of all possible values of a random variable X is called its range space.

    Events can be defined in the range space and their probabilities can be found.

    2012 from "A First Course in Quality Engineering: Integrating Statistical and Management Methods of Quality" by K.S. Krishnamoorthi. Reproduced by permission of Taylor and Francis Group, LLC, a division of Informa plc.

    Holly Ott Quality Engineering & Management Module 2.2 3

  • TUM School of Management Production and Supply Chain Management Prof Martin Grunow Technische Universitt Mnchen

    Random Variables

    Holly Ott Quality Engineering & Management Module 2.2 4

  • TUM School of Management Production and Supply Chain Management Prof Martin Grunow Technische Universitt Mnchen

    Random variables are of two kinds: 1. Discrete random variables 2. Continuous random variables.

    A discrete random variable takes a finite (or countably infinite)

    number of possible values.

    A continuous random variable takes an infinite number of possible values; it takes values in an interval.

    Random Variables

    2012 from "A First Course in Quality Engineering: Integrating Statistical and Management Methods of Quality" by K.S. Krishnamoorthi. Reproduced by permission of Taylor and Francis Group, LLC, a division of Informa plc.

    Holly Ott Quality Engineering & Management Module 2.2 5

  • TUM School of Management Production and Supply Chain Management Prof Martin Grunow Technische Universitt Mnchen

    Random Variables

    Holly Ott Quality Engineering & Management Module 2.2 6

    Foto: Lupo / pixelio.de

    Foto: Lupo /pixelio.de

    Foto: Antje Delater / pixelio.de

    Foto: neurolle - Rolf / pixelio.de

  • TUM School of Management Production and Supply Chain Management Prof Martin Grunow Technische Universitt Mnchen

    Random Variables

    Foto: Rosemarie Doll / www.pixelio.de

    Holly Ott Quality Engineering & Management Module 2.2 7

  • TUM School of Management Production and Supply Chain Management Prof Martin Grunow Technische Universitt Mnchen

    Ergebnisse sind normal-verteilt, wenn sie von vielen Einssen abhngen

    Height

    Frequency

    Reiner Hutwelker

    X = the height of people entering a test at the Munich Oktoberfest.

    Random Variables

    Holly Ott Quality Engineering & Management Module 2.2 8

    Foto: Michaela Schllhorn / pixelio.de

  • TUM School of Management Production and Supply Chain Management Prof Martin Grunow Technische Universitt Mnchen

    Ergebnisse sind normal-verteilt, wenn sie von vielen Einssen abhngen

    Height

    Frequency

    Reiner Hutwelker

    X = the height of people entering a test at the Munich Oktoberfest.

    Random Variables

    Holly Ott Quality Engineering & Management Module 2.2 9

    Foto: Michaela Schllhorn / pixelio.de

  • TUM School of Management Production and Supply Chain Management Prof Martin Grunow Technische Universitt Mnchen

    Exercise

    Now look at the next video to see an example of a random variable.

    Holly Ott Quality Engineering & Management Module 2.2 10

    Foto: Wolfgang Dirscherl / www.pixelio.de