STOR 155 Introductory Statistics (Chap 5) Lecture 14: Sampling Distributions for Counts and Proportions
|
|
- Baldric Quinn
- 5 years ago
- Views:
Transcription
1 The UNIVERSITY of NORTH CAROLINA at CHAPEL HILL STOR 155 Introductory Statistics (Chap 5) Lecture 14: Sampling Distributions for Counts and Proportions 5/31/11 Lecture 14 1
2 Statistic & Its Sampling Distribution A statistic is any numeric measure calculated from data. It is a random variable, its value varies from sample to sample. count/proportion: Ex: number/proportion of free throws made by a Tar Heel player who shoots 20 free throws in a practice sample mean Ex: average SAT score of a group of 10 students randomly selected from STAT 155 The probability distribution of a statistic is called its sampling distribution. It depends on the population distribution, and the sample size. 5/31/11 Lecture 14 2
3 Binomial Experiment n trials (with n fixed in advance). Each trial has two possible outcomes, success (S) and failure (F). The probability of success, p, remains the same from one trial to the next. The trials are independent, i.e. the outcome of each trial does not affect outcomes of other trials. 5/31/11 Lecture 14 3
4 Example The experiment: randomly draw n balls with replacement from an urn containing 10 red balls and 20 black balls. Let S represent {drawing a red ball} and F represent {drawing a black ball}. Then this is a binomial experiment with p =1/3. Q: Would it still be a binomial experiment if the balls were drawn without replacement? No! 5/31/11 Lecture 14 4
5 Binomial Distribution 5/31/11 Lecture 14 5
6 Do they follow binomial distributions (approximately)? X = number of stocks on the NY stock exchange whose prices increase today X = number of games the Tar Heel will win next season A couple decides to have children until they have a girl. X = number of boys the couple will have Answer: NO in all 3 cases. Why? 5/31/11 Lecture 14 6
7 Binomial Distribution If X ~ B(n, p), then X = np, 2 X = np(1-p). P(X=x) depends on n and p, which can be calculated using software or Table C (for some n and p), or a Binomial Formula (page 329) --- a simple argument given in class 5/31/11 Lecture 14 7
8 Binomial Table: for n 20, and certain values of p. Table C: Page T-6 5/31/11 Lecture 14 8
9 Credit Card Example Records show that 5% of the customers in a shoe store make their payments using a credit card. This morning 8 customers purchased shoes. Use the binomial table to answer the following questions. 1. Find the probability that exactly 6 customers did not use a credit card. X: number of customers who did not use a credit card. Then X ~ B(8, 0.95), which is not on the table. Y: number of customers who did use a credit card. Then Y ~ B(8, 0.05), which is on the table. P(X= 6) = P(Y = 2) = What is the probability that at least 3 customers used a credit card? (See the board ) 5/31/11 Lecture 14 9
10 Credit Card Example (continued) 3. What is the expected number of customers who used a credit card? Y = np = 8(.05) = What is the standard deviation of the number of customers who used a credit card? 2 Y = np (1 p) = 8(. 05)(.95) = The standard deviation is Y /31/11 Lecture 14 10
11 Parking Example (bad impact?) Sarah drives to work everyday, but does not own a parking permit. She decides to take her chances and risk getting a parking ticket each day. Suppose A parking permit for a week (5 days) cost $ 30. A parking fine costs $ 50. The probability of getting a parking ticket each day is 0.1. Her chances of getting a ticket each day is independent of other days. She can get only 1 ticket per day. What is her probability of getting at least 1 parking ticket in one week (5 days)? What is the expected number of parking tickets that Sarah will get per week? Is she better off paying the parking permit in the long run? 5/31/11 Lecture 14 11
12 Sample Proportion If X ~ B(n, p), the sample proportion is defined as X pˆ n # of successes sample size. mean & variance of a sample proportion: pˆ p, pˆ p(1 p) / n. 5/31/11 Lecture 14 12
13 Example: Clinton's vote 43% of the population voted for Clinton in Suppose we survey a sample of size 2300 and see if they voted for Clinton or not in We are interested in the sampling distribution of the sample proportion pˆ, for samples of size What's the mean and variance of pˆ? 5/31/11 Lecture 14 13
14 Count & Proportion of Success A Tar Heel basketball player is a 95% free throw shooter. Suppose he will shoot 5 free throws during each practice. X: number of free throws he makes in a practice. pˆ : proportion of free throws made during practice. pˆ P(X=3) = P( =0.6). Why? 5/31/11 Lecture 14 14
15 5/31/11 Lecture 14 15
16 Normal Approximation for Counts and Proportions Let X ~ B(n, p) and If n is large, then pˆ X / n. X is approx. N( np, np(1-p)) pˆ is approx. N( p, p(1-p) / n). Rule of Thumb: np 10, n(1 - p) 10. 5/31/11 Lecture 14 16
17 Switches Inspection A quality engineer selects an SRS of 100 switches from a large shipment for detailed inspection. Unknown to the engineer, 10% of the switches in the shipment fail to meet the specifications. Software tells us that the actual probability that no more than 9 of the switches in the sample fail inspection is P(X 9) = What will the normal approximation say? 5/31/11 Lecture 14 17
18 5/31/11 Lecture 14 18
19 Switches Inspection The normal approximation to the probability of no more than 9 bad switches is the area to the left of X = 9 under the normal curve. X np ( 100)(.1) 10, np(1 p) 100(.1)(.9) X 3. Using Table A, we have X P( X 9) P( ) P( Z.33) The approximation.3707 to the binomial probability of.4513 is not very accurate. In this case np = 10. 5/31/11 Lecture 14 19
20 5/31/11 Lecture 14 20
21 Continuity Correction The normal approximation is more accurate if we consider X=9 to extend from 8.5 to 9.5, X = 10 to extend from 9.5 to 10.5, and so on. Example (Cont.): P( X 9) P( X P( Z X ) P( 3.17) ) 3 5/31/11 Lecture 14 21
22 Continuity Correction P(X 8) replaced by P(X < 8.5) P(X 14) replaced by P(X > 13.5) P(X < 8) = P(X<=7) replaced by P(X < 7.5) For large n the effects of the continuity correction factor is very small and will be omitted. 5/31/11 Lecture 14 22
23 Coin Tossing Example Toss a fair coin 200 times, what is the probability that the total number of heads is between 90 and 110? X= the total number of heads X ~ B(200, 0.5). Want: P(90 X 110). X =200.5 = 100, X = ( ) 1/2 = With continuity correction: P(90 X 110) = P(X 110) - P(X 89) P( Z ( )/7.07) - P (Z ( )/7.07) = P (Z 1.48) - P (Z -1.48)= /31/11 Lecture 14 23
24 Normal Approximation for Sample Proportions Let X ~ B(n, p) and If n is large, then pˆ X / n. pˆ is approx. N( p, p(1-p) / n). Rule of Thumb: np 10, n(1 - p) 10. 5/31/11 Lecture 14 24
25 Example The Laurier company s brand has a market share of 30%. In a survey 1000 consumers were asked which brand they prefer. What is the probability that more than 32% of the respondents say they prefer the Laurier brand? Solution: The number of respondents who prefer Laurier is binomial with n = 1000 and p =.30. Also, np = 1000(.3) > 10, n(1-p) = 1000(1-.3) > 10. ˆ ( ˆ.32) p p P p P P( Z 1.38) (1 ) p p n /31/11 Lecture 14 25
26 Take Home Message Sampling distribution Binomial experiments Binomial distribution Binomial formula How to use Binomial Table Sample Proportion Normal approximation Continuity correction 5/31/11 Lecture 14 26
The binomial distribution p314
The binomial distribution p314 Example: A biased coin (P(H) = p = 0.6) ) is tossed 5 times. Let X be the number of H s. Fine P(X = 2). This X is a binomial r. v. The binomial setting p314 1. There are
More information***SECTION 8.1*** The Binomial Distributions
***SECTION 8.1*** The Binomial Distributions CHAPTER 8 ~ The Binomial and Geometric Distributions In practice, we frequently encounter random phenomenon where there are two outcomes of interest. For example,
More information2) There is a fixed number of observations n. 3) The n observations are all independent
Chapter 8 Binomial and Geometric Distributions The binomial setting consists of the following 4 characteristics: 1) Each observation falls into one of two categories success or failure 2) There is a fixed
More informationChapter 3 - Lecture 5 The Binomial Probability Distribution
Chapter 3 - Lecture 5 The Binomial Probability October 12th, 2009 Experiment Examples Moments and moment generating function of a Binomial Random Variable Outline Experiment Examples A binomial experiment
More informationChapter 8.1.notebook. December 12, Jan 17 7:08 PM. Jan 17 7:10 PM. Jan 17 7:17 PM. Pop Quiz Results. Chapter 8 Section 8.1 Binomial Distribution
Chapter 8 Section 8.1 Binomial Distribution Target: The student will know what the 4 characteristics are of a binomial distribution and understand how to use them to identify a binomial setting. Process
More informationMean of a Discrete Random variable. Suppose that X is a discrete random variable whose distribution is : :
Dr. Kim s Note (December 17 th ) The values taken on by the random variable X are random, but the values follow the pattern given in the random variable table. What is a typical value of a random variable
More informationA random variable (r. v.) is a variable whose value is a numerical outcome of a random phenomenon.
Chapter 14: random variables p394 A random variable (r. v.) is a variable whose value is a numerical outcome of a random phenomenon. Consider the experiment of tossing a coin. Define a random variable
More informationPart 1 In which we meet the law of averages. The Law of Averages. The Expected Value & The Standard Error. Where Are We Going?
1 The Law of Averages The Expected Value & The Standard Error Where Are We Going? Sums of random numbers The law of averages Box models for generating random numbers Sums of draws: the Expected Value Standard
More informationBinomial formulas: The binomial coefficient is the number of ways of arranging k successes among n observations.
Chapter 8 Notes Binomial and Geometric Distribution Often times we are interested in an event that has only two outcomes. For example, we may wish to know the outcome of a free throw shot (good or missed),
More informationMath 14 Lecture Notes Ch. 4.3
4.3 The Binomial Distribution Example 1: The former Sacramento King's DeMarcus Cousins makes 77% of his free throws. If he shoots 3 times, what is the probability that he will make exactly 0, 1, 2, or
More informationWhat is the probability of success? Failure? How could we do this simulation using a random number table?
Probability Ch.4, sections 4.2 & 4.3 Binomial and Geometric Distributions Name: Date: Pd: 4.2. What is a binomial distribution? How do we find the probability of success? Suppose you have three daughters.
More informationProbability & Statistics Chapter 5: Binomial Distribution
Probability & Statistics Chapter 5: Binomial Distribution Notes and Examples Binomial Distribution When a variable can be viewed as having only two outcomes, call them success and failure, it may be considered
More informationVIDEO 1. A random variable is a quantity whose value depends on chance, for example, the outcome when a die is rolled.
Part 1: Probability Distributions VIDEO 1 Name: 11-10 Probability and Binomial Distributions A random variable is a quantity whose value depends on chance, for example, the outcome when a die is rolled.
More informationSection 6.3 Binomial and Geometric Random Variables
Section 6.3 Binomial and Geometric Random Variables Mrs. Daniel AP Stats Binomial Settings A binomial setting arises when we perform several independent trials of the same chance process and record the
More informationName Period AP Statistics Unit 5 Review
Name Period AP Statistics Unit 5 Review Multiple Choice 1. Jay Olshansky from the University of Chicago was quoted in Chance News as arguing that for the average life expectancy to reach 100, 18% of people
More informationBinomial Distributions
Binomial Distributions (aka Bernouli s Trials) Chapter 8 Binomial Distribution an important class of probability distributions, which occur under the following Binomial Setting (1) There is a number n
More informationExamples: Random Variables. Discrete and Continuous Random Variables. Probability Distributions
Random Variables Examples: Random variable a variable (typically represented by x) that takes a numerical value by chance. Number of boys in a randomly selected family with three children. Possible values:
More informationchapter 13: Binomial Distribution Exercises (binomial)13.6, 13.12, 13.22, 13.43
chapter 13: Binomial Distribution ch13-links binom-tossing-4-coins binom-coin-example ch13 image Exercises (binomial)13.6, 13.12, 13.22, 13.43 CHAPTER 13: Binomial Distributions The Basic Practice of Statistics
More informationSTOR Lecture 7. Random Variables - I
STOR 435.001 Lecture 7 Random Variables - I Shankar Bhamidi UNC Chapel Hill 1 / 31 Example 1a: Suppose that our experiment consists of tossing 3 fair coins. Let Y denote the number of heads that appear.
More informationA random variable (r. v.) is a variable whose value is a numerical outcome of a random phenomenon.
Chapter 14: random variables p394 A random variable (r. v.) is a variable whose value is a numerical outcome of a random phenomenon. Consider the experiment of tossing a coin. Define a random variable
More informationStatistics Chapter 8
Statistics Chapter 8 Binomial & Geometric Distributions Time: 1.5 + weeks Activity: A Gaggle of Girls The Ferrells have 3 children: Jennifer, Jessica, and Jaclyn. If we assume that a couple is equally
More informationChapter 4 Discrete Random variables
Chapter 4 Discrete Random variables A is a variable that assumes numerical values associated with the random outcomes of an experiment, where only one numerical value is assigned to each sample point.
More informationSection 5 3 The Mean and Standard Deviation of a Binomial Distribution!
Section 5 3 The Mean and Standard Deviation of a Binomial Distribution! Previous sections required that you to find the Mean and Standard Deviation of a Binomial Distribution by using the values from a
More informationMATH1215: Mathematical Thinking Sec. 08 Spring Worksheet 9: Solution. x P(x)
N. Name: MATH: Mathematical Thinking Sec. 08 Spring 0 Worksheet 9: Solution Problem Compute the expected value of this probability distribution: x 3 8 0 3 P(x) 0. 0.0 0.3 0. Clearly, a value is missing
More informationExample 1: Identify the following random variables as discrete or continuous: a) Weight of a package. b) Number of students in a first-grade classroom
Section 5-1 Probability Distributions I. Random Variables A variable x is a if the value that it assumes, corresponding to the of an experiment, is a or event. A random variable is if it potentially can
More information8.1 Binomial Distributions
8.1 Binomial Distributions The Binomial Setting The 4 Conditions of a Binomial Setting: 1.Each observation falls into 1 of 2 categories ( success or fail ) 2 2.There is a fixed # n of observations. 3.All
More informationThe Binomial and Geometric Distributions. Chapter 8
The Binomial and Geometric Distributions Chapter 8 8.1 The Binomial Distribution A binomial experiment is statistical experiment that has the following properties: The experiment consists of n repeated
More information6. THE BINOMIAL DISTRIBUTION
6. THE BINOMIAL DISTRIBUTION Eg: For 1000 borrowers in the lowest risk category (FICO score between 800 and 850), what is the probability that at least 250 of them will default on their loan (thereby rendering
More informationSimple Random Sample
Simple Random Sample A simple random sample (SRS) of size n consists of n elements from the population chosen in such a way that every set of n elements has an equal chance to be the sample actually selected.
More informationChapter 4 Discrete Random variables
Chapter 4 Discrete Random variables A is a variable that assumes numerical values associated with the random outcomes of an experiment, where only one numerical value is assigned to each sample point.
More informationLesson 97 - Binomial Distributions IBHL2 - SANTOWSKI
Lesson 97 - Binomial Distributions IBHL2 - SANTOWSKI Opening Exercise: Example #: (a) Use a tree diagram to answer the following: You throwing a bent coin 3 times where P(H) = / (b) THUS, find the probability
More informationOpening Exercise: Lesson 91 - Binomial Distributions IBHL2 - SANTOWSKI
08-0- Lesson 9 - Binomial Distributions IBHL - SANTOWSKI Opening Exercise: Example #: (a) Use a tree diagram to answer the following: You throwing a bent coin times where P(H) = / (b) THUS, find the probability
More informationd) Find the standard deviation of the random variable X.
Q 1: The number of students using Math lab per day is found in the distribution below. x 6 8 10 12 14 P(x) 0.15 0.3 0.35 0.1 0.1 a) Find the mean for this probability distribution. b) Find the variance
More informationFINAL REVIEW W/ANSWERS
FINAL REVIEW W/ANSWERS ( 03/15/08 - Sharon Coates) Concepts to review before answering the questions: A population consists of the entire group of people or objects of interest to an investigator, while
More informationguessing Bluman, Chapter 5 2
Bluman, Chapter 5 1 guessing Suppose there is multiple choice quiz on a subject you don t know anything about. 15 th Century Russian Literature; Nuclear physics etc. You have to guess on every question.
More informationBinomal and Geometric Distributions
Binomal and Geometric Distributions Sections 3.2 & 3.3 Cathy Poliak, Ph.D. cathy@math.uh.edu Office in Fleming 11c Department of Mathematics University of Houston Lecture 7-2311 Cathy Poliak, Ph.D. cathy@math.uh.edu
More informationThe Central Limit Theorem. Sec. 8.2: The Random Variable. it s Distribution. it s Distribution
The Central Limit Theorem Sec. 8.1: The Random Variable it s Distribution Sec. 8.2: The Random Variable it s Distribution X p and and How Should You Think of a Random Variable? Imagine a bag with numbers
More informationRandom Variables CHAPTER 6.3 BINOMIAL AND GEOMETRIC RANDOM VARIABLES
Random Variables CHAPTER 6.3 BINOMIAL AND GEOMETRIC RANDOM VARIABLES Essential Question How can I determine whether the conditions for using binomial random variables are met? Binomial Settings When the
More informationSection Distributions of Random Variables
Section 8.1 - Distributions of Random Variables Definition: A random variable is a rule that assigns a number to each outcome of an experiment. Example 1: Suppose we toss a coin three times. Then we could
More informationMATH 264 Problem Homework I
MATH Problem Homework I Due to December 9, 00@:0 PROBLEMS & SOLUTIONS. A student answers a multiple-choice examination question that offers four possible answers. Suppose that the probability that the
More informationEcon 6900: Statistical Problems. Instructor: Yogesh Uppal
Econ 6900: Statistical Problems Instructor: Yogesh Uppal Email: yuppal@ysu.edu Lecture Slides 4 Random Variables Probability Distributions Discrete Distributions Discrete Uniform Probability Distribution
More informationLecture 7 Random Variables
Lecture 7 Random Variables Definition: A random variable is a variable whose value is a numerical outcome of a random phenomenon, so its values are determined by chance. We shall use letters such as X
More information5.4 Normal Approximation of the Binomial Distribution
5.4 Normal Approximation of the Binomial Distribution Bernoulli Trials have 3 properties: 1. Only two outcomes - PASS or FAIL 2. n identical trials Review from yesterday. 3. Trials are independent - probability
More informationChapter 5. Sampling Distributions
Lecture notes, Lang Wu, UBC 1 Chapter 5. Sampling Distributions 5.1. Introduction In statistical inference, we attempt to estimate an unknown population characteristic, such as the population mean, µ,
More informationSection Distributions of Random Variables
Section 8.1 - Distributions of Random Variables Definition: A random variable is a rule that assigns a number to each outcome of an experiment. Example 1: Suppose we toss a coin three times. Then we could
More informationChapter 6: Random Variables. Ch. 6-3: Binomial and Geometric Random Variables
Chapter : Random Variables Ch. -3: Binomial and Geometric Random Variables X 0 2 3 4 5 7 8 9 0 0 P(X) 3???????? 4 4 When the same chance process is repeated several times, we are often interested in whether
More information3. The n observations are independent. Knowing the result of one observation tells you nothing about the other observations.
Binomial and Geometric Distributions - Terms and Formulas Binomial Experiments - experiments having all four conditions: 1. Each observation falls into one of two categories we call them success or failure.
More information***SECTION 7.1*** Discrete and Continuous Random Variables
***SECTION 7.1*** Discrete and Continuous Random Variables UNIT 6 ~ Random Variables Sample spaces need not consist of numbers; tossing coins yields H s and T s. However, in statistics we are most often
More informationBinomial Random Variable - The count X of successes in a binomial setting
6.3.1 Binomial Settings and Binomial Random Variables What do the following scenarios have in common? Toss a coin 5 times. Count the number of heads. Spin a roulette wheel 8 times. Record how many times
More informationStatistics 6 th Edition
Statistics 6 th Edition Chapter 5 Discrete Probability Distributions Chap 5-1 Definitions Random Variables Random Variables Discrete Random Variable Continuous Random Variable Ch. 5 Ch. 6 Chap 5-2 Discrete
More informationChapter 6: Random Variables
Chapter 6: Random Variables Section 6.3 The Practice of Statistics, 4 th edition For AP* STARNES, YATES, MOORE Chapter 6 Random Variables 6.1 Discrete and Continuous Random Variables 6.2 Transforming and
More informationProbability Distributions. Definitions Discrete vs. Continuous Mean and Standard Deviation TI 83/84 Calculator Binomial Distribution
Probability Distributions Definitions Discrete vs. Continuous Mean and Standard Deviation TI 83/84 Calculator Binomial Distribution Definitions Random Variable: a variable that has a single numerical value
More information6.3: The Binomial Model
6.3: The Binomial Model The Normal distribution is a good model for many situations involving a continuous random variable. For experiments involving a discrete random variable, where the outcome of the
More informationChapter 8. Variables. Copyright 2004 Brooks/Cole, a division of Thomson Learning, Inc.
Chapter 8 Random Variables Copyright 2004 Brooks/Cole, a division of Thomson Learning, Inc. 8.1 What is a Random Variable? Random Variable: assigns a number to each outcome of a random circumstance, or,
More informationPROBABILITY DISTRIBUTIONS
CHAPTER 3 PROBABILITY DISTRIBUTIONS Page Contents 3.1 Introduction to Probability Distributions 51 3.2 The Normal Distribution 56 3.3 The Binomial Distribution 60 3.4 The Poisson Distribution 64 Exercise
More informationBinomial and Geometric Distributions
Binomial and Geometric Distributions Section 3.2 & 3.3 Cathy Poliak, Ph.D. cathy@math.uh.edu Office hours: T Th 2:30 pm - 5:15 pm 620 PGH Department of Mathematics University of Houston February 11, 2016
More informationSECTION 4.4: Expected Value
15 SECTION 4.4: Expected Value This section tells you why most all gambling is a bad idea. And also why carnival or amusement park games are a bad idea. Random Variables Definition: Random Variable A random
More information3. The n observations are independent. Knowing the result of one observation tells you nothing about the other observations.
Binomial and Geometric Distributions - Terms and Formulas Binomial Experiments - experiments having all four conditions: 1. Each observation falls into one of two categories we call them success or failure.
More informationBinomial Random Variables. Binomial Random Variables
Bernoulli Trials Definition A Bernoulli trial is a random experiment in which there are only two possible outcomes - success and failure. 1 Tossing a coin and considering heads as success and tails as
More informationSection Sampling Distributions for Counts and Proportions
Section 5.1 - Sampling Distributions for Counts and Proportions Statistics 104 Autumn 2004 Copyright c 2004 by Mark E. Irwin Distributions When dealing with inference procedures, there are two different
More information1. Steve says I have two children, one of which is a boy. Given this information, what is the probability that Steve has two boys?
Chapters 6 8 Review 1. Steve says I have two children, one of which is a boy. Given this information, what is the probability that Steve has two boys? (A) 1 (B) 3 1 (C) 3 (D) 4 1 (E) None of the above..
More information3.2 Binomial and Hypergeometric Probabilities
3.2 Binomial and Hypergeometric Probabilities Ulrich Hoensch Wednesday, January 23, 2013 Example An urn contains ten balls, exactly seven of which are red. Suppose five balls are drawn at random and with
More informationStat 20: Intro to Probability and Statistics
Stat 20: Intro to Probability and Statistics Lecture 13: Binomial Formula Tessa L. Childers-Day UC Berkeley 14 July 2014 By the end of this lecture... You will be able to: Calculate the ways an event can
More informationBinomial and multinomial distribution
1-Binomial distribution Binomial and multinomial distribution The binomial probability refers to the probability that a binomial experiment results in exactly "x" successes. The probability of an event
More informationChapter 11. Data Descriptions and Probability Distributions. Section 4 Bernoulli Trials and Binomial Distribution
Chapter 11 Data Descriptions and Probability Distributions Section 4 Bernoulli Trials and Binomial Distribution 1 Learning Objectives for Section 11.4 Bernoulli Trials and Binomial Distributions The student
More informationAP Statistics Test 5
AP Statistics Test 5 Name: Date: Period: ffl If X is a discrete random variable, the the mean of X and the variance of X are given by μ = E(X) = X xp (X = x); Var(X) = X (x μ) 2 P (X = x): ffl If X is
More informationOCR Statistics 1. Discrete random variables. Section 2: The binomial and geometric distributions. When to use the binomial distribution
Discrete random variables Section 2: The binomial and geometric distributions Notes and Examples These notes contain subsections on: When to use the binomial distribution Binomial coefficients Worked examples
More informationPROBABILITY AND STATISTICS, A16, TEST 1
PROBABILITY AND STATISTICS, A16, TEST 1 Name: Student number (1) (1.5 marks) i) Let A and B be mutually exclusive events with p(a) = 0.7 and p(b) = 0.2. Determine p(a B ) and also p(a B). ii) Let C and
More informationChapter 8: Binomial and Geometric Distributions
Chapter 8: Binomial and Geometric Distributions Section 8.1 Binomial Distributions The Practice of Statistics, 4 th edition For AP* STARNES, YATES, MOORE Section 8.1 Binomial Distribution Learning Objectives
More informationECON 214 Elements of Statistics for Economists 2016/2017
ECON 214 Elements of Statistics for Economists 2016/2017 Topic Probability Distributions: Binomial and Poisson Distributions Lecturer: Dr. Bernardin Senadza, Dept. of Economics bsenadza@ug.edu.gh College
More informationLecture Stat 302 Introduction to Probability - Slides 12
Lecture Stat 302 Introduction to Probability - Slides 12 AD March 2010 AD () March 2010 1 / 32 Hypergeometric Random Variable Consider a barrel or urn containing N balls of which m are white and N m are
More informationSection M Discrete Probability Distribution
Section M Discrete Probability Distribution A random variable is a numerical measure of the outcome of a probability experiment, so its value is determined by chance. Random variables are typically denoted
More informationMath 160 Professor Busken Chapter 5 Worksheets
Math 160 Professor Busken Chapter 5 Worksheets Name: 1. Find the expected value. Suppose you play a Pick 4 Lotto where you pay 50 to select a sequence of four digits, such as 2118. If you select the same
More informationAMS7: WEEK 4. CLASS 3
AMS7: WEEK 4. CLASS 3 Sampling distributions and estimators. Central Limit Theorem Normal Approximation to the Binomial Distribution Friday April 24th, 2015 Sampling distributions and estimators REMEMBER:
More informationSection Random Variables and Histograms
Section 3.1 - Random Variables and Histograms Definition: A random variable is a rule that assigns a number to each outcome of an experiment. Example 1: Suppose we toss a coin three times. Then we could
More informationLecture 9: Plinko Probabilities, Part III Random Variables, Expected Values and Variances
Physical Principles in Biology Biology 3550 Fall 2018 Lecture 9: Plinko Probabilities, Part III Random Variables, Expected Values and Variances Monday, 10 September 2018 c David P. Goldenberg University
More informationFall 2015 Math 141:505 Exam 3 Form A
Fall 205 Math 4:505 Exam 3 Form A Last Name: First Name: Exam Seat #: UIN: On my honor, as an Aggie, I have neither given nor received unauthorized aid on this academic work Signature: INSTRUCTIONS Part
More informationThe Binomial Probability Distribution
The Binomial Probability Distribution MATH 130, Elements of Statistics I J. Robert Buchanan Department of Mathematics Fall 2017 Objectives After this lesson we will be able to: determine whether a probability
More informationCHAPTER 6 Random Variables
CHAPTER 6 Random Variables 6.3 Binomial and Geometric Random Variables The Practice of Statistics, 5th Edition Starnes, Tabor, Yates, Moore Bedford Freeman Worth Publishers Binomial and Geometric Random
More informationTOPIC: PROBABILITY DISTRIBUTIONS
TOPIC: PROBABILITY DISTRIBUTIONS There are two types of random variables: A Discrete random variable can take on only specified, distinct values. A Continuous random variable can take on any value within
More information4.1 Probability Distributions
Probability and Statistics Mrs. Leahy Chapter 4: Discrete Probability Distribution ALWAYS KEEP IN MIND: The Probability of an event is ALWAYS between: and!!!! 4.1 Probability Distributions Random Variables
More informationMath 1070 Sample Exam 2 Spring 2015
University of Connecticut Department of Mathematics Math 1070 Sample Exam 2 Spring 2015 Name: Instructor Name: Section: Exam 2 will cover Sections 4.6-4.7, 5.3-5.4, 6.1-6.4, and F.1-F.4. This sample exam
More informationSTUDY SET 1. Discrete Probability Distributions. x P(x) and x = 6.
STUDY SET 1 Discrete Probability Distributions 1. Consider the following probability distribution function. Compute the mean and standard deviation of. x 0 1 2 3 4 5 6 7 P(x) 0.05 0.16 0.19 0.24 0.18 0.11
More informationLecture 23. STAT 225 Introduction to Probability Models April 4, Whitney Huang Purdue University. Normal approximation to Binomial
Lecture 23 STAT 225 Introduction to Probability Models April 4, 2014 approximation Whitney Huang Purdue University 23.1 Agenda 1 approximation 2 approximation 23.2 Characteristics of the random variable:
More informationStat511 Additional Materials
Binomial Random Variable Stat511 Additional Materials The first discrete RV that we will discuss is the binomial random variable. The binomial random variable is a result of observing the outcomes from
More informationMA 1125 Lecture 14 - Expected Values. Wednesday, October 4, Objectives: Introduce expected values.
MA 5 Lecture 4 - Expected Values Wednesday, October 4, 27 Objectives: Introduce expected values.. Means, Variances, and Standard Deviations of Probability Distributions Two classes ago, we computed the
More informationUnit 04 Review. Probability Rules
Unit 04 Review Probability Rules A sample space contains all the possible outcomes observed in a trial of an experiment, a survey, or some random phenomenon. The sum of the probabilities for all possible
More informationChapter 5: Probability models
Chapter 5: Probability models 1. Random variables: a) Idea. b) Discrete and continuous variables. c) The probability function (density) and the distribution function. d) Mean and variance of a random variable.
More informationDiscrete Random Variables and Probability Distributions. Stat 4570/5570 Based on Devore s book (Ed 8)
3 Discrete Random Variables and Probability Distributions Stat 4570/5570 Based on Devore s book (Ed 8) Random Variables We can associate each single outcome of an experiment with a real number: We refer
More information= 0.35 (or ˆp = We have 20 independent trials, each with probability of success (heads) equal to 0.5, so X has a B(20, 0.5) distribution.
Chapter 5 Solutions 51 (a) n = 1500 (the sample size) (b) The Yes count seems like the most reasonable choice, but either count is defensible (c) X = 525 (or X = 975) (d) ˆp = 525 1500 = 035 (or ˆp = 975
More informationSection 7.5 The Normal Distribution. Section 7.6 Application of the Normal Distribution
Section 7.6 Application of the Normal Distribution A random variable that may take on infinitely many values is called a continuous random variable. A continuous probability distribution is defined by
More informationII - Probability. Counting Techniques. three rules of counting. 1multiplication rules. 2permutations. 3combinations
II - Probability Counting Techniques three rules of counting 1multiplication rules 2permutations 3combinations Section 2 - Probability (1) II - Probability Counting Techniques 1multiplication rules In
More informationProbability Distribution Unit Review
Probability Distribution Unit Review Topics: Pascal's Triangle and Binomial Theorem Probability Distributions and Histograms Expected Values, Fair Games of chance Binomial Distributions Hypergeometric
More informationAP Statistics Section 6.1 Day 1 Multiple Choice Practice. a) a random variable. b) a parameter. c) biased. d) a random sample. e) a statistic.
A Statistics Section 6.1 Day 1 ultiple Choice ractice Name: 1. A variable whose value is a numerical outcome of a random phenomenon is called a) a random variable. b) a parameter. c) biased. d) a random
More information1 / * / * / * / * / * The mean winnings are $1.80
DISCRETE vs. CONTINUOUS BASIC DEFINITION Continuous = things you measure Discrete = things you count OFFICIAL DEFINITION Continuous data can take on any value including fractions and decimals You can zoom
More informationSampling Distributions For Counts and Proportions
Sampling Distributions For Counts and Proportions IPS Chapter 5.1 2009 W. H. Freeman and Company Objectives (IPS Chapter 5.1) Sampling distributions for counts and proportions Binomial distributions for
More informationX P(X=x) E(X)= V(X)= S.D(X)= X P(X=x) E(X)= V(X)= S.D(X)=
1. X 0 1 2 P(X=x) 0.2 0.4 0.4 E(X)= V(X)= S.D(X)= X 100 200 300 400 P(X=x) 0.1 0.2 0.5 0.2 E(X)= V(X)= S.D(X)= 2. A day trader buys an option on a stock that will return a $100 profit if the stock goes
More information5.4 Normal Approximation of the Binomial Distribution Lesson MDM4U Jensen
5.4 Normal Approximation of the Binomial Distribution Lesson MDM4U Jensen Review From Yesterday Bernoulli Trials have 3 properties: 1. 2. 3. Binomial Probability Distribution In a binomial experiment with
More informationElementary Statistics Lecture 5
Elementary Statistics Lecture 5 Sampling Distributions Chong Ma Department of Statistics University of South Carolina Chong Ma (Statistics, USC) STAT 201 Elementary Statistics 1 / 24 Outline 1 Introduction
More informationExample. Chapter 8 Probability Distributions and Statistics Section 8.1 Distributions of Random Variables
Chapter 8 Probability Distributions and Statistics Section 8.1 Distributions of Random Variables You are dealt a hand of 5 cards. Find the probability distribution table for the number of hearts. Graph
More information