Resource Web Search

Description

Using your favorite search engine, locate online resources that best explain to you particular topics found within your assigned chapter readings for this week. You will need to identify a topic within the chapter you read this week and locate a web resource that best explains the topic to you. For each resource please include the chapter the selected website corresponds to, a functional link to the website, and your rationale for selecting the website.

Chapter 1, "Statistics: The Art and Science of Learning from Data"

These slides have been augmented by your instructor to include tips, hints, include tips, hints, shortcuts, and shortcuts, and instructions on using technology to solve problems in the problems in the homework assignments and on assignments and on exams.exams.
Copyright © 2017, 20013, and 2009, Pearson Education, Inc. 1-3Using Data to Answer Statistical QuestionsSection 1.1
1-4Copyright © 2017, 20013, and 2009, Pearson Education, Inc.The information we gather with experiments and surveys is collectively called data. Example: Experiment on low carbohydrate dietData could be measurements on subjects before and after the experiment.Example: Survey on the effectiveness of a TV adData could be a percentage of people who went to Starbucks since the ad aired.Data and Examples of Collecting Data
1-5Copyright © 2017, 20013, and 2009, Pearson Education, Inc.Statistics is the art and science of: Designing studiesAnalyzing the data produced by these studies Translating data into knowledge and understanding of the world around us define Statistics
1-6Copyright © 2017, 20013, and 2009, Pearson Education, Inc.The three main components of statistics for answering a statistical question:Design: Planning how to obtain dataDescription: Summarizing the data obtainedInference: Making decisions and predictionsReasons for Using Statistical Methods
1-7Copyright © 2017, 20013, and 2009, Pearson Education, Inc.Design questions:How to conduct the experimentHow to select people for the survey to ensure trustworthy resultsExamples:Planning the methods for data collection to study the effects of Vitamin CFor a marketing study, how do you select people for your survey so you’ll get data that provide accurate predictions about future sales?Design
1-8Copyright © 2017, 20013, and 2009, Pearson Education, Inc.Description:Summarize the raw data and present it in a useful format (e.g., average, charts, or graphs).Examples:It is more informative to use a few numbers or a graph to summarize the data, such as an average amount of TV watchedA graph displaying how a number of hours of TV watched per day relates to the number of hours per week exercising.Description
Inference: Make decisions or predictions based on the data.Examples:Has there been global warming over the past decade?Is having the death penalty as a possible punishment associated with a reduction in violent crime?Does student performance in school depend on the amount of money spent per student, the size of the classes, or the teachers’ salaries?Inference
1-10Copyright © 2017, 20013, and 2009, Pearson Education, Inc.Probability: A framework for quantifying how likely various possible outcomes are.Example: If Brown were actually going to lose the election (that is if he were supported by less than half of all voters), what’s the chance that an exit poll of 3889 voters would show support by 53.1% of the voters?Probability
Copyright © 2017, 20013, and 2009, Pearson Education, Inc. 1-11Section 1.2Sample Versus Population
1-12Copyright © 2017, 20013, and 2009, Pearson Education, Inc.Subjects The entities that we measure in a studySubjects could be individuals, schools, countries, days, etc.We Observe Samples but are Interested in Populations
1-13Copyright © 2017, 20013, and 2009, Pearson Education, Inc.Population: The total set of subjects in which we are interested sample: Subset of the population for whom we have data population and SamplePopulationSample
1-14Copyright © 2017, 20013, and 2009, Pearson Education, Inc.The purpose was to predict the outcome of the 2010 gubernatorial election in California.An exit poll sampled 3889 of the 9.5 million people who voted. Define the sample and the population for this exit poll.The population was the 9.5 million people who voted in the election.The sample was the 3889 voters who were interviewed in the exit poll.Example: An Exit Poll

The purpose was to predict the outcome of the 2010 gubernatorial election in California.An exit poll sampled 3889 of the 9.5 million people who voted. Define the sample and the population for this exit poll.The population was the 9.5 million people who voted in the election.The sample was the 3889 voters who were interviewed in the exit poll.Example: An Exit Poll
1-15Copyright © 2017, 20013, and 2009, Pearson Education, Inc.Descriptive Statistics refers to methods for summarizing the collected data. Summaries consist of graphs and numbers such as averages and percentages.Inferential statistics refers to methods of making decisions or predictions about a population based on data obtained from a sample of that population.Descriptive Statistics and Inferential Statistics
1-16Copyright © 2017, 20013, and 2009, Pearson Education, Inc.Descriptive Statistics ExampleFigure 1.1 Educational Attainment, Based on a Sample of 78,000 Households in the 2013 Current Population Survey.
1-17Copyright © 2017, 20013, and 2009, Pearson Education, Inc.Suppose we’d like to know what people think about controls over the sales of handguns. We can study results from a recent poll of 834 Florida residents.In that poll, 54.0% of the sampled subjects said they favored controls over the sales of handguns.We are 95% confident that the percentage of all adult Floridians favoring control over sales of handguns falls between 50.6% and 57.4%.Inferential Statistics Example
1-18Copyright © 2017, 20013, and 2009, Pearson Education, Inc.A parameter is a numerical summary of the population. Example: Percentage of the population of all Florida residents favoring handgun control.A statistic is a numerical summary of a sample taken from the population.Example: 54.0% of the sampled subjects said they favored controls over the sales of handguns.Sample Statistics and Population ParametersTip: Both parameters and population begin with p.Both statistics and samples begin with s.
1-19Copyright © 2017, 20013, and 2009, Pearson Education, Inc.Random sampling allows us to make powerful inferences about populations.Randomness is also crucial to performing experiments well.Randomness and Variability
1-20Copyright © 2017, 20013, and 2009, Pearson Education, Inc.Measurements may vary from person to person, and just as people vary, so do samples vary. Measurements may vary from sample to sample.Predictions will, therefore, be more accurate for larger samples. Differences between measurements in a larger sample tend to cancel each other out, reducing the overall amount of variation.Randomness and Variability
1-21Copyright © 2017, 20013, and 2009, Pearson Education, Inc.Estimation from Surveys with Random SamplingData from sample surveys is frequently used to estimate population percentages.Example: A Gallup poll recently reported that 30% of Americans worried that they might not be able to pay health insurance costs during the next 12 months.
1-22Copyright © 2017, 20013, and 2009, Pearson Education, Inc.Estimation from Surveys with Random SamplingMargin of error is a measure of the expected variability from one random sample to the next random sample.Example: A margin of error of plus or minus 3 percentage points means it is very likely that the population percentage is no more than 3% lower or 3% higher than the reported sample percentage.
When the difference between the results for two treatments is so large that it would be rare to see such a difference by ordinary random variation, we say that the results are statistically significant. Testing and Statistical Significance
Copyright © 2017, 20013, and 2009, Pearson Education, Inc. 1-24Section 1.3Using Calculators and Computers
1-25Copyright © 2017, 20013, and 2009, Pearson Education, Inc. Using (and Misusing) Statistics Software and CalculatorsMINITAB, JMP, StatCrunch, SPSS, and R are popular statistical software packages on college campuses. The TI-83 +, TI-84, TI-89, and TI-Inspire family calculators, which have similar output, are useful as portable tools for generating simple statistics and graphs. Using Technology The problem is that a computer will perform the statistical analysis you request whether or not its use is valid for the given situation. You, not technology, must select valid analyses. Using Calculators and Computers
1-26Copyright © 2017, 20013, and 2009, Pearson Education, Inc. Data filesLarge sets of data are typically organized in a spreadsheet format known as a data file.Each row contains measurements for a particular subject.Each column contains measurements for a particular characteristic. DatabasesAn existing archive collection of data filesNot all databases give reliable information. Before you give credence to such data, verify that the data are from a trustworthy source. Using Calculators and Computers
1-27Copyright © 2017, 20013, and 2009, Pearson Education, Inc.Your access to the online course materials includes several web apps, organized by chapter.To access these web apps, click Tools for Success and then, under Media, click WebApps.These web apps are useful for performing activities that illustrate the ideas of statistics.You can use web apps instead of StatCrunch or the TI-84 calculator to find solutions to homework and exam problems.When applicable, you can load data from an example given in the PowerPoint lecture. You can also load your own data.The web apps allow you to simulate what would happen in a real-life situation through repeated sampling (without having to collect any data at all)Using Web Apps
1-28Copyright © 2017, 20013, and 2009, Pearson Education, Inc.Example: Calculating an Intervalcontinued
1-29Copyright © 2017, 20013, and 2009, Pearson Education, Inc.Example (continued)continued
1-30Copyright © 2017, 20013, and 2009, Pearson Education, Inc.Example (continued)

Sample Solution