Making Sense of Cents

Size: px
Start display at page:

Download "Making Sense of Cents"

Transcription

1 Name: Date: Making Sense of Cents Exploring the Central Limit Theorem Many of the variables that you have studied so far in this class have had a normal distribution. You have used a table of the normal distribution to answer questions about a randomly selected individual or a random sample taken from a normal distribution. Many distributions, however, are not normal or any other standard shape. If the shape of a distribution isn t normal, can we make any inferences about the mean of a random sample from that distribution? Objective Discover the central limit theorem by observing the shape, mean, and standard deviation of the sampling distribution of the mean for samples taken from a distribution that is not normal. Activity Take a random sample of 25 pennies and make a list of the dates on each penny. Next to each date, write the age of the penny by subtracting the date from this year. Date of Penny Age Date of Penny Age What do you think the shape of the distribution of all the ages of pennies from students in the class will look like?

2 Make a histogram using a frequency distribution with 10 classes of the ages of all the pennies in the class. Estimate the mean and standard deviation of the distribution. Confirm your estimates by actual computation using the graphing calculator. In List 1 you should put in all of the raw data values. USE THE #YEARS OLD AS YOUR RAW DATA VALUES (Do not use the sample statistics, as you and your partner s pennies are your population, so you must compute the mean and then you may use the population statistic given on the calculator.) Mean = µ = Standard Deviation= σ =

3 Take a random sample of size 5 from your pile of pennies, and compute the mean age of your sample. Sketch the distribution of the class s data by drawing the number line on the board with the results of the class s computation. Sketch the curve that approximates the distribution. Sampling Distribution of Sample Means, n = 5 What are the actual mean and standard deviation of this distribution? Again, use the population statistic and the raw data values in your list.

4 Take a random sample of size 10 from the ages of your pennies, and compute the mean age of your sample. Place your sample means on a number line on the board. Sketch the distribution of the class s data by drawing the number line on the board with the results of the class s computation. Sketch the curve that approximates the distribution. Sampling Distribution of Sample Means, n = 10 What are the actual mean and standard deviation of this distribution? Again, use the population statistic and the raw data values in your list.

5 Take a random sample of size 25 from the ages of your pennies, and compute the mean age of your sample. Place your sample means on a number line on the board. Sketch the distribution of the class s data by drawing the number line on the board with the results of the class s computation. Sketch the curve that approximates the distribution. Sampling Distribution of Sample Means, n = 25 What are the actual mean and standard deviation of this distribution? Again, use the population statistic and the raw data values in your list. What are the actual mean and standard deviation of this distribution?

6 Look at the four histograms the class has constructed. What can you say about the shape of the histogram as n increases? What can you say about the center of the histogram as n increases? What can you say about the spread of the histogram as n increases? Shape, center, and spread of the sampling distribution make up the central limit theorem. Without looking in your textbook, write a statement of what you think the central limit theorem says. The distributions you constructed for samples of size 1, 5, 10, and 25 are called sampling distributions of the sample mean. Sketch what you anticipate the curve for the sampling distribution of the sample mean to look like for samples of size 36. Write a paragraph explaining what you learned from this activity. Find an example of a use for the Central Limit Theorem in the real world.

Central Limit Theorem

Central Limit Theorem Central Limit Theorem Lots of Samples 1 Homework Read Sec 6-5. Discussion Question pg 329 Do Ex 6-5 8-15 2 Objective Use the Central Limit Theorem to solve problems involving sample means 3 Sample Means

More information

MLLunsford 1. Activity: Central Limit Theorem Theory and Computations

MLLunsford 1. Activity: Central Limit Theorem Theory and Computations MLLunsford 1 Activity: Central Limit Theorem Theory and Computations Concepts: The Central Limit Theorem; computations using the Central Limit Theorem. Prerequisites: The student should be familiar with

More information

MA131 Lecture 8.2. The normal distribution curve can be considered as a probability distribution curve for normally distributed variables.

MA131 Lecture 8.2. The normal distribution curve can be considered as a probability distribution curve for normally distributed variables. Normal distribution curve as probability distribution curve The normal distribution curve can be considered as a probability distribution curve for normally distributed variables. The area under the normal

More information

A continuous random variable is one that can theoretically take on any value on some line interval. We use f ( x)

A continuous random variable is one that can theoretically take on any value on some line interval. We use f ( x) Section 6-2 I. Continuous Probability Distributions A continuous random variable is one that can theoretically take on any value on some line interval. We use f ( x) to represent a probability density

More information

SECTION 6.2 (DAY 1) TRANSFORMING RANDOM VARIABLES NOVEMBER 16 TH, 2017

SECTION 6.2 (DAY 1) TRANSFORMING RANDOM VARIABLES NOVEMBER 16 TH, 2017 SECTION 6.2 (DAY 1) TRANSFORMING RANDOM VARIABLES NOVEMBER 16 TH, 2017 TODAY S OBJECTIVES Describe the effects of transforming a random variable by: adding or subtracting a constant multiplying or dividing

More information

Distribution of the Sample Mean

Distribution of the Sample Mean Distribution of the Sample Mean MATH 130, Elements of Statistics I J. Robert Buchanan Department of Mathematics Fall 2018 Experiment (1 of 3) Suppose we have the following population : 4 8 1 2 3 4 9 1

More information

The Normal Distribution

The Normal Distribution 5.1 Introduction to Normal Distributions and the Standard Normal Distribution Section Learning objectives: 1. How to interpret graphs of normal probability distributions 2. How to find areas under the

More information

The Normal Probability Distribution

The Normal Probability Distribution 1 The Normal Probability Distribution Key Definitions Probability Density Function: An equation used to compute probabilities for continuous random variables where the output value is greater than zero

More information

6 Central Limit Theorem. (Chs 6.4, 6.5)

6 Central Limit Theorem. (Chs 6.4, 6.5) 6 Central Limit Theorem (Chs 6.4, 6.5) Motivating Example In the next few weeks, we will be focusing on making statistical inference about the true mean of a population by using sample datasets. Examples?

More information

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. Chapter 6 Exam A Name The given values are discrete. Use the continuity correction and describe the region of the normal distribution that corresponds to the indicated probability. 1) The probability of

More information

Normal Curves & Sampling Distributions

Normal Curves & Sampling Distributions Chapter 7 Name Normal Curves & Sampling Distributions Section 7.1 Graphs of Normal Probability Distributions Objective: In this lesson you learned how to graph a normal curve and apply the empirical rule

More information

Chapter 7 Study Guide: The Central Limit Theorem

Chapter 7 Study Guide: The Central Limit Theorem Chapter 7 Study Guide: The Central Limit Theorem Introduction Why are we so concerned with means? Two reasons are that they give us a middle ground for comparison and they are easy to calculate. In this

More information

Study Ch. 7.3, # 63 71

Study Ch. 7.3, # 63 71 GOALS: 1. Understand the distribution of the sample mean. 2. Understand that using the distribution of the sample mean with sufficiently large sample sizes enables us to use parametric statistics for distributions

More information

As you draw random samples of size n, as n increases, the sample means tend to be normally distributed.

As you draw random samples of size n, as n increases, the sample means tend to be normally distributed. The Central Limit Theorem The central limit theorem (clt for short) is one of the most powerful and useful ideas in all of statistics. The clt says that if we collect samples of size n with a "large enough

More information

Normal Probability Distributions

Normal Probability Distributions Normal Probability Distributions Properties of Normal Distributions The most important probability distribution in statistics is the normal distribution. Normal curve A normal distribution is a continuous

More information

CHAPTER 6 Random Variables

CHAPTER 6 Random Variables CHAPTER 6 Random Variables 6.2 Transforming and Combining Random Variables The Practice of Statistics, 5th Edition Starnes, Tabor, Yates, Moore Bedford Freeman Worth Publishers 6.2 Reading Quiz (T or F)

More information

AP Statistics Chapter 6 - Random Variables

AP Statistics Chapter 6 - Random Variables AP Statistics Chapter 6 - Random 6.1 Discrete and Continuous Random Objective: Recognize and define discrete random variables, and construct a probability distribution table and a probability histogram

More information

Chapter Seven: Confidence Intervals and Sample Size

Chapter Seven: Confidence Intervals and Sample Size Chapter Seven: Confidence Intervals and Sample Size A point estimate is: The best point estimate of the population mean µ is the sample mean X. Three Properties of a Good Estimator 1. Unbiased 2. Consistent

More information

Lecture Slides. Elementary Statistics Tenth Edition. by Mario F. Triola. and the Triola Statistics Series. Slide 1

Lecture Slides. Elementary Statistics Tenth Edition. by Mario F. Triola. and the Triola Statistics Series. Slide 1 Lecture Slides Elementary Statistics Tenth Edition and the Triola Statistics Series by Mario F. Triola Slide 1 Chapter 6 Normal Probability Distributions 6-1 Overview 6-2 The Standard Normal Distribution

More information

Chapter 15: Sampling distributions

Chapter 15: Sampling distributions =true true Chapter 15: Sampling distributions Objective (1) Get "big picture" view on drawing inferences from statistical studies. (2) Understand the concept of sampling distributions & sampling variability.

More information

ECON 214 Elements of Statistics for Economists 2016/2017

ECON 214 Elements of Statistics for Economists 2016/2017 ECON 214 Elements of Statistics for Economists 2016/2017 Topic The Normal Distribution Lecturer: Dr. Bernardin Senadza, Dept. of Economics bsenadza@ug.edu.gh College of Education School of Continuing and

More information

CHAPTER 7 INTRODUCTION TO SAMPLING DISTRIBUTIONS

CHAPTER 7 INTRODUCTION TO SAMPLING DISTRIBUTIONS CHAPTER 7 INTRODUCTION TO SAMPLING DISTRIBUTIONS Note: This section uses session window commands instead of menu choices CENTRAL LIMIT THEOREM (SECTION 7.2 OF UNDERSTANDABLE STATISTICS) The Central Limit

More information

Section Introduction to Normal Distributions

Section Introduction to Normal Distributions Section 6.1-6.2 Introduction to Normal Distributions 2012 Pearson Education, Inc. All rights reserved. 1 of 105 Section 6.1-6.2 Objectives Interpret graphs of normal probability distributions Find areas

More information

ECON 214 Elements of Statistics for Economists

ECON 214 Elements of Statistics for Economists ECON 214 Elements of Statistics for Economists Session 7 The Normal Distribution Part 1 Lecturer: Dr. Bernardin Senadza, Dept. of Economics Contact Information: bsenadza@ug.edu.gh College of Education

More information

4.2 Probability Distributions

4.2 Probability Distributions 4.2 Probability Distributions Definition. A random variable is a variable whose value is a numerical outcome of a random phenomenon. The probability distribution of a random variable tells us what the

More information

Figure 1: 2πσ is said to have a normal distribution with mean µ and standard deviation σ. This is also denoted

Figure 1: 2πσ is said to have a normal distribution with mean µ and standard deviation σ. This is also denoted Figure 1: Math 223 Lecture Notes 4/1/04 Section 4.10 The normal distribution Recall that a continuous random variable X with probability distribution function f(x) = 1 µ)2 (x e 2σ 2πσ is said to have a

More information

Y i % (% ( ( ' & ( # % s 2 = ( ( Review - order of operations. Samples and populations. Review - order of operations. Review - order of operations

Y i % (% ( ( ' & ( # % s 2 = ( ( Review - order of operations. Samples and populations. Review - order of operations. Review - order of operations Review - order of operations Samples and populations Estimating with uncertainty s 2 = # % # n & % % $ n "1'% % $ n ) i=1 Y i 2 n & "Y 2 ' Review - order of operations Review - order of operations 1. Parentheses

More information

AP * Statistics Review

AP * Statistics Review AP * Statistics Review Normal Models and Sampling Distributions Teacher Packet AP* is a trademark of the College Entrance Examination Board. The College Entrance Examination Board was not involved in the

More information

The Central Limit Theorem

The Central Limit Theorem Section 6-5 The Central Limit Theorem I. Sampling Distribution of Sample Mean ( ) Eample 1: Population Distribution Table 2 4 6 8 P() 1/4 1/4 1/4 1/4 μ (a) Find the population mean and population standard

More information

Stat 213: Intro to Statistics 9 Central Limit Theorem

Stat 213: Intro to Statistics 9 Central Limit Theorem 1 Stat 213: Intro to Statistics 9 Central Limit Theorem H. Kim Fall 2007 2 unknown parameters Example: A pollster is sure that the responses to his agree/disagree questions will follow a binomial distribution,

More information

INFERENTIAL STATISTICS REVISION

INFERENTIAL STATISTICS REVISION INFERENTIAL STATISTICS REVISION PREMIUM VERSION PREVIEW WWW.MATHSPOINTS.IE/SIGN-UP/ 2016 LCHL Paper 2 Question 9 (a) (i) Data on earnings were published for a particular country. The data showed that the

More information

CH 5 Normal Probability Distributions Properties of the Normal Distribution

CH 5 Normal Probability Distributions Properties of the Normal Distribution Properties of the Normal Distribution Example A friend that is always late. Let X represent the amount of minutes that pass from the moment you are suppose to meet your friend until the moment your friend

More information

Lecture 6: Chapter 6

Lecture 6: Chapter 6 Lecture 6: Chapter 6 C C Moxley UAB Mathematics 3 October 16 6.1 Continuous Probability Distributions Last week, we discussed the binomial probability distribution, which was discrete. 6.1 Continuous Probability

More information

Statistical Intervals (One sample) (Chs )

Statistical Intervals (One sample) (Chs ) 7 Statistical Intervals (One sample) (Chs 8.1-8.3) Confidence Intervals The CLT tells us that as the sample size n increases, the sample mean X is close to normally distributed with expected value µ and

More information

CHAPTER 5 Sampling Distributions

CHAPTER 5 Sampling Distributions CHAPTER 5 Sampling Distributions 5.1 The possible values of p^ are 0, 1/3, 2/3, and 1. These correspond to getting 0 persons with lung cancer, 1 with lung cancer, 2 with lung cancer, and all 3 with lung

More information

Section 6.5. The Central Limit Theorem

Section 6.5. The Central Limit Theorem Section 6.5 The Central Limit Theorem Idea Will allow us to combine the theory from 6.4 (sampling distribution idea) with our central limit theorem and that will allow us the do hypothesis testing in the

More information

Sampling Distributions

Sampling Distributions AP Statistics Ch. 7 Notes Sampling Distributions A major field of statistics is statistical inference, which is using information from a sample to draw conclusions about a wider population. Parameter:

More information

Chapter 6: The Normal Distribution

Chapter 6: The Normal Distribution Chapter 6: The Normal Distribution Diana Pell Section 6.1: Normal Distributions Note: Recall that a continuous variable can assume all values between any two given values of the variables. Many continuous

More information

Chapter 9: Sampling Distributions

Chapter 9: Sampling Distributions Chapter 9: Sampling Distributions 9. Introduction This chapter connects the material in Chapters 4 through 8 (numerical descriptive statistics, sampling, and probability distributions, in particular) with

More information

Chapter 7: SAMPLING DISTRIBUTIONS & POINT ESTIMATION OF PARAMETERS

Chapter 7: SAMPLING DISTRIBUTIONS & POINT ESTIMATION OF PARAMETERS Chapter 7: SAMPLING DISTRIBUTIONS & POINT ESTIMATION OF PARAMETERS Part 1: Introduction Sampling Distributions & the Central Limit Theorem Point Estimation & Estimators Sections 7-1 to 7-2 Sample data

More information

Chapter 6: The Normal Distribution

Chapter 6: The Normal Distribution Chapter 6: The Normal Distribution Diana Pell Section 6.1: Normal Distributions Note: Recall that a continuous variable can assume all values between any two given values of the variables. Many continuous

More information

Shifting and rescaling data distributions

Shifting and rescaling data distributions Shifting and rescaling data distributions It is useful to consider the effect of systematic alterations of all the values in a data set. The simplest such systematic effect is a shift by a fixed constant.

More information

Lecture 9. Probability Distributions. Outline. Outline

Lecture 9. Probability Distributions. Outline. Outline Outline Lecture 9 Probability Distributions 6-1 Introduction 6- Probability Distributions 6-3 Mean, Variance, and Expectation 6-4 The Binomial Distribution Outline 7- Properties of the Normal Distribution

More information

Expected Value of a Random Variable

Expected Value of a Random Variable Knowledge Article: Probability and Statistics Expected Value of a Random Variable Expected Value of a Discrete Random Variable You're familiar with a simple mean, or average, of a set. The mean value of

More information

Chapter Four: Introduction To Inference 1/50

Chapter Four: Introduction To Inference 1/50 Chapter Four: Introduction To Inference 1/50 4.1 Introduction 2/50 4.1 Introduction In this chapter you will learn the rationale underlying inference. You will also learn to apply certain inferential techniques.

More information

Chapter 7. Sampling Distributions

Chapter 7. Sampling Distributions Chapter 7 Sampling Distributions Section 7.1 Sampling Distributions and the Central Limit Theorem Sampling Distributions Sampling distribution The probability distribution of a sample statistic. Formed

More information

NORMAL RANDOM VARIABLES (Normal or gaussian distribution)

NORMAL RANDOM VARIABLES (Normal or gaussian distribution) NORMAL RANDOM VARIABLES (Normal or gaussian distribution) Many variables, as pregnancy lengths, foot sizes etc.. exhibit a normal distribution. The shape of the distribution is a symmetric bell shape.

More information

MATH 264 Problem Homework I

MATH 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 information

Continuous Random Variables and the Normal Distribution

Continuous Random Variables and the Normal Distribution Chapter 6 Continuous Random Variables and the Normal Distribution Continuous random variables are used to approximate probabilities where there are many possible outcomes or an infinite number of possible

More information

Lecture 9. Probability Distributions

Lecture 9. Probability Distributions Lecture 9 Probability Distributions Outline 6-1 Introduction 6-2 Probability Distributions 6-3 Mean, Variance, and Expectation 6-4 The Binomial Distribution Outline 7-2 Properties of the Normal Distribution

More information

What type of distribution is this? tml

What type of distribution is this?  tml Warm Up Calculate the average Broncos score for the 2013 Season! 24, 27, 10, 10, 34, 37, 20, 51, 35, 31, 27, 28, 45, 33, 35, 52, 52, 37, 41, 49, 24, 26 What type of distribution is this? http://www.mathsisfun.com/data/quincunx.h

More information

Using the Central Limit Theorem It is important for you to understand when to use the CLT. If you are being asked to find the probability of the

Using the Central Limit Theorem It is important for you to understand when to use the CLT. If you are being asked to find the probability of the Using the Central Limit Theorem It is important for you to understand when to use the CLT. If you are being asked to find the probability of the mean, use the CLT for the mean. If you are being asked to

More information

Uniform Probability Distribution. Continuous Random Variables &

Uniform Probability Distribution. Continuous Random Variables & Continuous Random Variables & What is a Random Variable? It is a quantity whose values are real numbers and are determined by the number of desired outcomes of an experiment. Is there any special Random

More information

Module 4: Probability

Module 4: Probability Module 4: Probability 1 / 22 Probability concepts in statistical inference Probability is a way of quantifying uncertainty associated with random events and is the basis for statistical inference. Inference

More information

Review: Population, sample, and sampling distributions

Review: Population, sample, and sampling distributions Review: Population, sample, and sampling distributions A population with mean µ and standard deviation σ For instance, µ = 0, σ = 1 0 1 Sample 1, N=30 Sample 2, N=30 Sample 100000000000 InterquartileRange

More information

6.1 Graphs of Normal Probability Distributions:

6.1 Graphs of Normal Probability Distributions: 6.1 Graphs of Normal Probability Distributions: Normal Distribution one of the most important examples of a continuous probability distribution, studied by Abraham de Moivre (1667 1754) and Carl Friedrich

More information

Honors Statistics. Daily Agenda

Honors Statistics. Daily Agenda Honors Statistics Aug 23-8:26 PM Daily Agenda Aug 23-8:31 PM 1 Write a program to generate random numbers. I've decided to give them free will. A Skip 4, 12, 16 Apr 25-10:55 AM Toss 4 times Suppose you

More information

Value (x) probability Example A-2: Construct a histogram for population Ψ.

Value (x) probability Example A-2: Construct a histogram for population Ψ. Calculus 111, section 08.x The Central Limit Theorem notes by Tim Pilachowski If you haven t done it yet, go to the Math 111 page and download the handout: Central Limit Theorem supplement. Today s lecture

More information

The Central Limit Theorem (Solutions) COR1-GB.1305 Statistics and Data Analysis

The Central Limit Theorem (Solutions) COR1-GB.1305 Statistics and Data Analysis The Central Limit Theorem (Solutions) COR1-GB1305 Statistics and Data Analysis 1 You draw a random sample of size n = 64 from a population with mean µ = 50 and standard deviation σ = 16 From this, you

More information

STAT:2010 Statistical Methods and Computing. Using density curves to describe the distribution of values of a quantitative

STAT:2010 Statistical Methods and Computing. Using density curves to describe the distribution of values of a quantitative STAT:10 Statistical Methods and Computing Normal Distributions Lecture 4 Feb. 6, 17 Kate Cowles 374 SH, 335-0727 kate-cowles@uiowa.edu 1 2 Using density curves to describe the distribution of values of

More information

Chapter Seven. The Normal Distribution

Chapter Seven. The Normal Distribution Chapter Seven The Normal Distribution 7-1 Introduction Many continuous variables have distributions that are bellshaped and are called approximately normally distributed variables, such as the heights

More information

Math 227 Elementary Statistics. Bluman 5 th edition

Math 227 Elementary Statistics. Bluman 5 th edition Math 227 Elementary Statistics Bluman 5 th edition CHAPTER 6 The Normal Distribution 2 Objectives Identify distributions as symmetrical or skewed. Identify the properties of the normal distribution. Find

More information

Chapter 4 and Chapter 5 Test Review Worksheet

Chapter 4 and Chapter 5 Test Review Worksheet Name: Date: Hour: Chapter 4 and Chapter 5 Test Review Worksheet You must shade all provided graphs, you must round all z-scores to 2 places after the decimal, you must round all probabilities to at least

More information

Activity #17b: Central Limit Theorem #2. 1) Explain the Central Limit Theorem in your own words.

Activity #17b: Central Limit Theorem #2. 1) Explain the Central Limit Theorem in your own words. Activity #17b: Central Limit Theorem #2 1) Explain the Central Limit Theorem in your own words. Importance of the CLT: You can standardize and use normal distribution tables to calculate probabilities

More information

1. Variability in estimates and CLT

1. Variability in estimates and CLT Unit3: Foundationsforinference 1. Variability in estimates and CLT Sta 101 - Fall 2015 Duke University, Department of Statistical Science Dr. Çetinkaya-Rundel Slides posted at http://bit.ly/sta101_f15

More information

Sampling Distributions

Sampling Distributions Section 8.1 119 Sampling Distributions Section 8.1 C H A P T E R 8 4Example 2 (pg. 378) Sampling Distribution of the Sample Mean The heights of 3-year-old girls are normally distributed with μ=38.72 and

More information

I. Standard Error II. Standard Error III. Standard Error 2.54

I. Standard Error II. Standard Error III. Standard Error 2.54 1) Original Population: Match the standard error (I, II, or III) with the correct sampling distribution (A, B, or C) and the correct sample size (1, 5, or 10) I. Standard Error 1.03 II. Standard Error

More information

FORMULA FOR STANDARD DEVIATION:

FORMULA FOR STANDARD DEVIATION: Chapter 5 Review: Statistics Textbook p.210-282 Summary: p.238-239, p.278-279 Practice Questions p.240, p.280-282 Z- Score Table p.592 Key Concepts: Central Tendency, Standard Deviation, Graphing, Normal

More information

STA Module 3B Discrete Random Variables

STA Module 3B Discrete Random Variables STA 2023 Module 3B Discrete Random Variables Learning Objectives Upon completing this module, you should be able to 1. Determine the probability distribution of a discrete random variable. 2. Construct

More information

5.1 Mean, Median, & Mode

5.1 Mean, Median, & Mode 5.1 Mean, Median, & Mode definitions Mean: Median: Mode: Example 1 The Blue Jays score these amounts of runs in their last 9 games: 4, 7, 2, 4, 10, 5, 6, 7, 7 Find the mean, median, and mode: Example 2

More information

Chapter 7 Sampling Distributions and Point Estimation of Parameters

Chapter 7 Sampling Distributions and Point Estimation of Parameters Chapter 7 Sampling Distributions and Point Estimation of Parameters Part 1: Sampling Distributions, the Central Limit Theorem, Point Estimation & Estimators Sections 7-1 to 7-2 1 / 25 Statistical Inferences

More information

No, because np = 100(0.02) = 2. The value of np must be greater than or equal to 5 to use the normal approximation.

No, because np = 100(0.02) = 2. The value of np must be greater than or equal to 5 to use the normal approximation. 1) If n 100 and p 0.02 in a binomial experiment, does this satisfy the rule for a normal approximation? Why or why not? No, because np 100(0.02) 2. The value of np must be greater than or equal to 5 to

More information

3. Probability Distributions and Sampling

3. Probability Distributions and Sampling 3. Probability Distributions and Sampling 3.1 Introduction: the US Presidential Race Appendix 2 shows a page from the Gallup WWW site. As you probably know, Gallup is an opinion poll company. The page

More information

Measure of Variation

Measure of Variation Measure of Variation Variation is the spread of a data set. The simplest measure is the range. Range the difference between the maximum and minimum data entries in the set. To find the range, the data

More information

MATH 104 CHAPTER 5 page 1 NORMAL DISTRIBUTION

MATH 104 CHAPTER 5 page 1 NORMAL DISTRIBUTION MATH 104 CHAPTER 5 page 1 NORMAL DISTRIBUTION We have examined discrete random variables, those random variables for which we can list the possible values. We will now look at continuous random variables.

More information

The Central Limit Theorem: Homework

The Central Limit Theorem: Homework The Central Limit Theorem: Homework EXERCISE 1 X N(60, 9). Suppose that you form random samples of 25 from this distribution. Let X be the random variable of averages. Let X be the random variable of sums.

More information

MAS1403. Quantitative Methods for Business Management. Semester 1, Module leader: Dr. David Walshaw

MAS1403. Quantitative Methods for Business Management. Semester 1, Module leader: Dr. David Walshaw MAS1403 Quantitative Methods for Business Management Semester 1, 2018 2019 Module leader: Dr. David Walshaw Additional lecturers: Dr. James Waldren and Dr. Stuart Hall Announcements: Written assignment

More information

The normal distribution is a theoretical model derived mathematically and not empirically.

The normal distribution is a theoretical model derived mathematically and not empirically. Sociology 541 The Normal Distribution Probability and An Introduction to Inferential Statistics Normal Approximation The normal distribution is a theoretical model derived mathematically and not empirically.

More information

Examples: Random Variables. Discrete and Continuous Random Variables. Probability Distributions

Examples: 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 information

The Central Limit Theorem. Sec. 8.2: The Random Variable. it s Distribution. it s Distribution

The 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 information

WebAssign Math 3680 Homework 5 Devore Fall 2013 (Homework)

WebAssign Math 3680 Homework 5 Devore Fall 2013 (Homework) WebAssign Math 3680 Homework 5 Devore Fall 2013 (Homework) Current Score : 135.45 / 129 Due : Friday, October 11 2013 11:59 PM CDT Mirka Martinez Applied Statistics, Math 3680-Fall 2013, section 2, Fall

More information

Example - Let X be the number of boys in a 4 child family. Find the probability distribution table:

Example - Let X be the number of boys in a 4 child family. Find the probability distribution table: Chapter8 Probability Distributions and Statistics Section 8.1 Distributions of Random Variables tthe value of the result of the probability experiment is a RANDOM VARIABLE. Example - Let X be the number

More information

CHAPTER 5 SAMPLING DISTRIBUTIONS

CHAPTER 5 SAMPLING DISTRIBUTIONS CHAPTER 5 SAMPLING DISTRIBUTIONS Sampling Variability. We will visualize our data as a random sample from the population with unknown parameter μ. Our sample mean Ȳ is intended to estimate population mean

More information

1 Sampling Distributions

1 Sampling Distributions 1 Sampling Distributions 1.1 Statistics and Sampling Distributions When a random sample is selected the numerical descriptive measures calculated from such a sample are called statistics. These statistics

More information

Chapter 7: Sampling Distributions Chapter 7: Sampling Distributions

Chapter 7: Sampling Distributions Chapter 7: Sampling Distributions Chapter 7: Sampling Distributions Objectives: Students will: Define a sampling distribution. Contrast bias and variability. Describe the sampling distribution of a proportion (shape, center, and spread).

More information

Lecture 3. Sampling distributions. Counts, Proportions, and sample mean.

Lecture 3. Sampling distributions. Counts, Proportions, and sample mean. Lecture 3 Sampling distributions. Counts, Proportions, and sample mean. Statistical Inference: Uses data and summary statistics (mean, variances, proportions, slopes) to draw conclusions about a population

More information

8.1 Estimation of the Mean and Proportion

8.1 Estimation of the Mean and Proportion 8.1 Estimation of the Mean and Proportion Statistical inference enables us to make judgments about a population on the basis of sample information. The mean, standard deviation, and proportions of a population

More information

11.5: Normal Distributions

11.5: Normal Distributions 11.5: Normal Distributions 11.5.1 Up to now, we ve dealt with discrete random variables, variables that take on only a finite (or countably infinite we didn t do these) number of values. A continuous random

More information

Discrete Probability Distribution

Discrete Probability Distribution 1 Discrete Probability Distribution Key Definitions Discrete Random Variable: Has a countable number of values. This means that each data point is distinct and separate. Continuous Random Variable: Has

More information

2011 Pearson Education, Inc

2011 Pearson Education, Inc Statistics for Business and Economics Chapter 4 Random Variables & Probability Distributions Content 1. Two Types of Random Variables 2. Probability Distributions for Discrete Random Variables 3. The Binomial

More information

Point Estimation. Stat 4570/5570 Material from Devore s book (Ed 8), and Cengage

Point Estimation. Stat 4570/5570 Material from Devore s book (Ed 8), and Cengage 6 Point Estimation Stat 4570/5570 Material from Devore s book (Ed 8), and Cengage Point Estimation Statistical inference: directed toward conclusions about one or more parameters. We will use the generic

More information

Normal Probability Distributions

Normal Probability Distributions C H A P T E R Normal Probability Distributions 5 Section 5.2 Example 3 (pg. 248) Normal Probabilities Assume triglyceride levels of the population of the United States are normally distributed with a mean

More information

6.2.1 Linear Transformations

6.2.1 Linear Transformations 6.2.1 Linear Transformations In Chapter 2, we studied the effects of transformations on the shape, center, and spread of a distribution of data. Recall what we discovered: 1. Adding (or subtracting) a

More information

Data Analysis and Statistical Methods Statistics 651

Data Analysis and Statistical Methods Statistics 651 Data Analysis and Statistical Methods Statistics 651 http://www.stat.tamu.edu/~suhasini/teaching.html Suhasini Subba Rao The binomial: mean and variance Recall that the number of successes out of n, denoted

More information

Section 3.4 The Normal Distribution

Section 3.4 The Normal Distribution Section 3.4 The Normal Distribution Properties of the Normal Distribution Curve 1. We denote the normal random variable with X = x. 2. The curve has a peak at x = µ. 3. The curve is symmetric about the

More information

Section 7.5 The Normal Distribution. Section 7.6 Application of the Normal Distribution

Section 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 information

STATISTICS - CLUTCH CH.9: SAMPLING DISTRIBUTIONS: MEAN.

STATISTICS - CLUTCH CH.9: SAMPLING DISTRIBUTIONS: MEAN. !! www.clutchprep.com SAMPLING DISTRIBUTIONS (MEANS) As of now, the normal distributions we have worked with only deal with the population of observations Example: What is the probability of randomly selecting

More information

Business Statistics 41000: Probability 4

Business Statistics 41000: Probability 4 Business Statistics 41000: Probability 4 Drew D. Creal University of Chicago, Booth School of Business February 14 and 15, 2014 1 Class information Drew D. Creal Email: dcreal@chicagobooth.edu Office:

More information

Introduction to Statistics I

Introduction to Statistics I Introduction to Statistics I Keio University, Faculty of Economics Continuous random variables Simon Clinet (Keio University) Intro to Stats November 1, 2018 1 / 18 Definition (Continuous random variable)

More information

Normal Model (Part 1)

Normal Model (Part 1) Normal Model (Part 1) Formulas New Vocabulary The Standard Deviation as a Ruler The trick in comparing very different-looking values is to use standard deviations as our rulers. The standard deviation

More information