Slide 1Practice ProblemsPractice ProblemsAdditional Reading and ExamplesMotivating ExampleSlide 6StatisticsPopulationParameterParameterSlide 11SampleStatisticStatisticInferenceExample 1Example 1Example 1Example 1Example 1Example 1Example 1Example 1Example 1Example 1Example 1Example 1Example 1Example 1Example 1Example 1Example 1DistributionDescriptive StatisticsInferential StatisticsReplication / RepetitionConstantVariableQualitative or Categorical VariableQuantitative VariableDiscrete Quantitative VariableContinuous Quantitative VariableExample 2Example 2Example 2Example 2Example 2Example 2Example 2Example 2Example 2Example 2Example 2Example 2Motivating Example ContinuedMotivating Example ContinuedMotivating Example ContinuedMotivating Example ContinuedMotivating Example ContinuedMotivating Example ContinuedMotivating Example ContinuedMotivating Example ContinuedMotivating Example ContinuedMotivating Example ContinuedSTAT 210Lecture 2Introduction and Basic DefinitionsAugust 28, 2017Practice ProblemsAt the end of each section there are a set of Practice Problems.These problems reemphasize the concepts that have been discussed in the material proceeding them. You should work these problems outside of class to best prepare for the tests.Solutions can be found in the back of the supplement.Relevant problems are practice problems associated with that day’s lecture. Recommended problems are problems that test questions are likely to be similar to.Practice ProblemsPages 9 and 10Relevant problems: I.1 through I.5Recommended problems: I.1, I.3 and I.4.Additional Reading and ExamplesRead the Additional Reading and Examples on pages 6 through 8.Motivating ExampleIt is of interest to determine what percentage of all VCU students who, when asked to list three things that they enjoy doing, include “shopping” on their list.Top HatStatisticsStatistics is a science that involves the extraction of information from numerical data obtained during an experiment or from a sample. It involves the design of the experiment or sampling procedure and the collection of the data, the analysis of the data, and making inferences (statements) about the population based upon information in a sample.The entire group of individuals about which the researcher wants information.Examples: 1. All United States citizens 2. All male students at VCU 3. All sections of all courses taught this semester at VCUPopulationParameterSome characteristic of the population that the researcher wants to measure.Examples: 1. Proportion of US. citizens who voted in the 2008 Presidential election 2. Average (mean) height of all male students at VCU 3. Proportion of all sections of all courses taught by adjunct (part-time) facultyParameterSome characteristic of the population that the researcher wants to measure.Parameters are typically denoted with Greek letters. For example, the mean of a population is denoted using the Greek letter m (read mu) and the proportion of successes in a population is denoted by the Greek letter p (read pi).What is the parameter of interest?Mean (m) Proportion (p) (m1-m2)Is the population standard deviation s known?Yes – use Z No – use tDo you want a confidence interval or a test?CI TestALWAYS CHECK THE ASSUMPTIONSSampleA subset of the population that is contacted and examined to gather information.Example: when the population is all male VCU students, a sample would be all male students in this classStatisticA descriptive measure, computed from data in a sample, that can be expressed or evaluated numerically.Example: For the sample of male students in this class, one can compute the average height of these students. This average height is a statistic.StatisticA descriptive measure, computed from data in a sample, that can be expressed or evaluated numerically.Statistics are typically denoted with symbols involving regular English letters. For example, the mean of the sample is usually denoted by X (read X-bar) and the proportion of successes in a sample is denoted by p (read p-hat).InferenceA statement about a population based on the data collected in a sample.Example: To estimate the average height of all male VCU students we can compute the average height of the male students in this class.Example 1Example 1Population = ???Example 1Population = the 204 countries and territories eligible to win a medal at the OlympicsExample 1Population = the 204 countries and territories eligible to win a medal at the OlympicsSample = ???Example 1Population = the 204 countries and territories eligible to win a medal at the OlympicsSample = the 20 countries or territories that were selected for further informationExample 1Population = the 204 countries and territories eligible to win a medal at the OlympicsSample = the 20 countries or territories that were selected for further information(a). 204 – ???Example 1Population = the 204 countries and territories eligible to win a medal at the OlympicsSample = the 20 countries or territories that were selected for further information(a). 204 – parameter - it is the number of countries or territories in the populationExample 1Population = the 204 countries and territories eligible to win a medal at the OlympicsSample = the 20 countries or territories that were selected for further information(a). 204 – parameter - it is the number in the population(b). 20 – ???Example 1Population = the 204 countries and territories eligible to win a medal at the OlympicsSample = the 20 countries or territories that were selected for further information(a). 204 – parameter - it is the number in the population(b). 20 – statistic - it is the number of countries or territories in the sampleExample 1Population = the 204 countries and territories eligible to win a medal at the OlympicsSample = the 20 countries or territories that were selected for further information(a). 204 – parameter - it is the number in the population(b). 20 – statistic - it is the number of countries in the sample(c). 65% - ???Example 1Population = the 204 countries and territories eligible to win a medal at the OlympicsSample = the 20 countries or territories that were selected for further information(a). 204 – parameter - it is the number in the population(b). 20 – statistic - it is the number of countries in the sample(c). 65% - statistic - it is the percentage of the sample that had at least one athlete win a gold medalExample
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