商务与经济统计 第14版 Ch03 Descriptive Statistics- Numerical Measures.ppt

Statistics for Business and Economics (14e)Metric VersionAnderson, Sweeney, Williams, Camm, Cochran, Fry, Ohlmann? 2020 Cengage Learning1 Chapter 3 - Descriptive Statistics: Numerical Measures3.1 - Measures of Location3.2 - Measures of Variability3.3 - Measures of Distribution Shape, Relative Location, and Detecting Outliers3.4 - Five-Number Summaries and Box Plots3.5 - Measures of Association Between Two Variables3.6 - Data Dashboards: Adding Numerical Measures to Improve Effectiveness2 Numerical MeasuresIf the measures are computed for data from a sample, they are called sample statistics.If the measures are computed for data from a population, they are called population parameters.A sample statistic is referred to as the point estimator of the corresponding population parameter.3 Measures of LocationMeanMedianModeWeighted MeanGeometric MeanPercentilesQuartiles4 Mean?5 ?Seventy efficiency apartments were randomly sampled in a college town. The monthly rents for these apartments are listed below.5255405505655806106755305405505705856156755305405505705906256805355455505725906256905355455505755906257005355455605756006357005355455605756006497005355455605806006507005405505655806006707155405505655806106707156 Median (1 of 4)The median of a data set is the value in the middle when the data items are arranged in ascending order.Whenever a data set has extreme values, the median is the preferred measure of central location.The median is the measure of location most often reported for annual income and property value data.A few extremely large incomes or property values can inflate the mean.7 Median (2 of 4)Here we have an odd number of observations:7 observations: 26, 18, 27, 12, 14, 27, and 19.Rewritten in ascending order: 12, 14, 18, 19, 26, 27, and 27.The median is the middle value in this list, so the median = 19.8 Median (3 of 4)Here we have an even number of observations:8 observations: 26, 18, 27, 12, 14, 27, 19, and 30.Rewritten in ascending order: 12,