Chapter7.6 M2 Sample Data & Populations EQ: How can we collect data from populations?

Slides:

Advertisements

Similar presentations

Chapter 6 Sampling and Sampling Distributions

Advertisements

Determining the Sample Plan

Sullivan – Fundamentals of Statistics – 2 nd Edition – Chapter 1 Section 2 – Slide 1 of 22 Chapter 1 Section 2 Observational Studies, Experiments, and.

Discussion Sampling Methods

© 2003 Prentice-Hall, Inc.Chap 1-1 Business Statistics: A First Course (3 rd Edition) Chapter 1 Introduction and Data Collection.

© 2004 Prentice-Hall, Inc.Chap 1-1 Basic Business Statistics (9 th Edition) Chapter 1 Introduction and Data Collection.

Relationship Between Sample Data and Population Values You will encounter many situations in business where a sample will be taken from a population, and.

© 2002 Prentice-Hall, Inc.Chap 1-1 Statistics for Managers using Microsoft Excel 3 rd Edition Chapter 1 Introduction and Data Collection.

Introduction to Statistics

Chap 1-1 Chapter 1 Why Study Statistics? EF 507 QUANTITATIVE METHODS FOR ECONOMICS AND FINANCE FALL 2008.

Chapter 7 Sampling and Sampling Distributions

Why sample? Diversity in populations Practicality and cost.

Chapter 1 Introduction and Data Collection

Chapter 1 The Where, Why, and How of Data Collection

7-1 Chapter Seven SAMPLING DESIGN. 7-2 Sampling What is it? –Drawing a conclusion about the entire population from selection of limited elements in a.

T T07-01 Sample Size Effect – Normal Distribution Purpose Allows the analyst to analyze the effect that sample size has on a sampling distribution.

Chapter 1: Data Collection

Part III: Inference Topic 6 Sampling and Sampling Distributions

Statistical Methods Descriptive Statistics Inferential Statistics Collecting and describing data. Making decisions based on sample data.

Chapter12 Determining the Sample Plan. The Sample Plan is the process followed to select units from the population to be used in the sample.

Determining the Sample Plan

Basic Business Statistics (8th Edition)

Copyright ©2005 Brooks/Cole, a division of Thomson Learning, Inc. How to Get a Good Sample Chapter 4.

WARM – UP 1.Phrase a survey or experimental question in such a way that you would obtain a Proportional Response. 2.Phrase a survey or experimental question.

A P STATISTICS LESSON 9 – 1 ( DAY 1 ) SAMPLING DISTRIBUTIONS.

Business Statistics: A Decision-Making Approach, 6e © 2005 Prentice-Hall, Inc. Chap 1-1 Business Statistics: A Decision-Making Approach 6 th Edition Chapter.

Chapter 24 Survey Methods and Sampling Techniques

Chapter 2: Sampling and Surveys Section 2.1: Samples, Good and Bad.

4.2 Statistics Notes What are Good Ways and Bad Ways to Sample?

Chapter 1 Introduction and Data Collection

Sampling Distributions

1-3 Data Collection and Sampling Techniques Surveys are the most common method of collecting data. Three methods of surveying are: 1) Telephone surveys.

Chapter 6 Lecture 3 Sections: 6.4 – 6.5.

Sampling Distributions Chapter 7. The Concept of a Sampling Distribution Repeated samples of the same size are selected from the same population. Repeated.

Chapter 12 Sample Surveys

Data Gathering Techniques. Essential Question: What are the different methods for gathering data about a population?

How do I collect sample data from population? 7.6 Sample Data and Populations Example 1 Collect data by randomly sampling A gym has 467 female members.

CHAPTER 12 DETERMINING THE SAMPLE PLAN. Important Topics of This Chapter Differences between population and sample. Sampling frame and frame error. Developing.

Basic Business Statistics

Chapter 5 Section 1 – Part 2. Samples: Good & Bad What makes a sample bad? What type of “bad” sampling did we discuss previously?

Statistics for Managers Using Microsoft Excel, 4e © 2004 Prentice-Hall, Inc. Chap 1-1 Statistics for Managers Using Microsoft ® Excel 4 th Edition Chapter.

Estimation This is our introduction to the field of inferential statistics. We already know why we want to study samples instead of entire populations,

Lecture 4. Sampling is the process of selecting a small number of elements from a larger defined target group of elements such that the information gathered.

Chap 1-1 Chapter 1 Introduction and Data Collection Business Statistics.

EXPERIMENTAL DATA PROCESSING Ilya I. Ogol. There are three kinds of lies: lies, damned lies, and statistics.

An Overview of Statistics Section 1.1. Ch1 Larson/Farber 2 Statistics is the science of collecting, organizing, analyzing, and interpreting data in order.

Chapter One Data Collection 1.2 Observational Studies; Simple Random Sampling.

Chapter 10: Introduction to Statistical Inference.

Chapter 7 Sampling Distributions. Sampling Distribution of the Mean Inferential statistics –conclusions about population Distributions –if you examined.

Data Collection & Sampling Dr. Guerette. Gathering Data Three ways a researcher collects data: Three ways a researcher collects data: By asking questions.

1. When I give you the signal, you will have 10 seconds to look at a slide and make a guess as to the average number of m&m’s per pile. Do not use pencil.

A Course In Business Statistics, 4th © 2006 Prentice-Hall, Inc. Chap 1-1 A Course In Business Statistics 4 th Edition Chapter 1 The Where, Why, and How.

Chapter 6 Lecture 3 Sections: 6.4 – 6.5. Sampling Distributions and Estimators What we want to do is find out the sampling distribution of a statistic.

Chapter 5 Sampling Distributions. The Concept of Sampling Distributions Parameter – numerical descriptive measure of a population. It is usually unknown.

Basic Business Statistics, 8e © 2002 Prentice-Hall, Inc. Chap 1-1 Inferential Statistics for Forecasting Dr. Ghada Abo-zaid Inferential Statistics for.

1 of 29Visit UMT online at Prentice Hall 2003 Chapter 1, STAT125Basic Business Statistics STATISTICS FOR MANAGERS University of Management.

Topic II Statistic. Vocabulary  Parameter : In a statistic study, data are collected and used to answer questions about a population characteristic.

Sullivan – Statistics: Informed Decisions Using Data – 2 nd Edition – Chapter 1 Section 2 – Slide 1 of 21 Chapter 1 Section 2 Observational Studies, Experiments,

Ch1 Larson/Farber 1 Elementary Statistics Math III Introduction to Statistics.

Sampling Distributions & Sample Means Movie Clip.

Review Normal Distributions –Draw a picture. –Convert to standard normal (if necessary) –Use the binomial tables to look up the value. –In the case of.

Sampling Distributions Chapter 18. Sampling Distributions A parameter is a number that describes the population. In statistical practice, the value of.

Statistics in Management

Section 4.2 Random Sampling.

Probability and Statistics

Random Sampling and Combinations

Introduction to Statistics

Probability and Statistics

Chapter 1 Why Study Statistics?

Chapter 1 Why Study Statistics?

Presentation transcript:

Chapter7.6 M2 Sample Data & Populations EQ: How can we collect data from populations?

The Sample Plan is the process followed to select units from the population to be used in the sample

Basic Concepts in Samples and Sampling Population: the entire group under study as defined by research objectives. Sometimes called the “universe.” Researchers define populations in specific terms such as heads of households, individual person types, families, types of retail outlets, etc. Population geographic location and time of study are also considered.

Basic Concepts in Samples and Sampling…cont. Statistic: a numerical description of a sample characteristic parameter: a numerical description of a population characteristic. The mean of a population is an example of a population parameter. Population mean: The true mean of the entire population

Reasons for Taking a Sample Practical considerations such as cost and population size Inability of researcher to analyze large quantities of data potentially generated by a census Samples can produce sound results if proper rules are followed for the draw

Probability Sampling Methods Simple Random Sampling Simple random sampling: the probability of being selected is “known and equal” for all members of the population Blind Draw Method (e.g. names “placed in a hat” and then drawn randomly) Random Numbers Method (all items in the sampling frame given numbers, numbers then drawn using table or computer program) Advantages: Known and equal chance of selection Easy method when there is an electronic database

Ex 1: Collect data by random sampling A country club has 345 social members and 876 golf members. The president of the country club wants to form a random sample of 20 social members and a separate random sample of 50 golf members to answer some survey questions. Each social member has a membership number from and each golf member has a membership number from 1001 to Use a graphing calculator to select the members who will participate in each random sample.

The Solution Keystrokes: math, prb, 5(randInt) Use the random integer feature of a graphing calculator to generate 20 random integers between 1 and 345. Use the arrows to scroll over and see the rest of the random values. Document the values – this list makes up your random sample of social members. Now use the random integer feature to generate 50 random integers between 1001 and Use the arrows to scroll over and see the rest of the random values. Document the values – this list makes up your random sample of golf members.

Ex2: Compare statistics and parameters A school’s math club wants to know how many hours students spend on math homework each week. Savannah and Miguel, two students in the math club, collect separate random samples. Their results are displayed on page 274 of the M2 textbook. The population mean is 11.9 and the population standard deviation is about 6.7. Compare the means and the standard deviations of the random samples to the population parameters.

Let’s compare results Savannah X-bar: 9.8 Std. deviation: 3.6 Miquel X-bar: 12.7 Std. deviation: about 4.2 The mean of Savannah’s sample is less than the population mean. The mean of Miguel’s sample is greater than the population mean. The standard deviations of both samples are less than the population standard deviation. This indicates that the samples are less varied than the entire population.

Homework page 276 #1-7 all, 9