Chapter 2.2（课件）- 《统计学基础（英文版）》同步教学（人民大学版）

Chapter Descriptive Statistics 2 1 Copyright 2019, 2015, 2012, Pearson Education, Inc. 1 Larson/Farber 6th ed Chapter 1 Chapter Outline 2.1 Frequency Distributions and Their Graphs 2.2 More Graphs and Displays 2.3 Measures of Central Tendency 2.4 Measures of Variation 2.5 Measures of Position 1 Copyright 2019, 2015, 2012, Pearson Education, Inc. Section 2.2 More Graphs and Displays 1 Copyright 2019, 2015, 2012, Pearson Education, Inc. Section 2.2 Objectives How to graph and interpret quantitative data using stem-and-leaf plots and dot plots How to graph and interpret qualitative data using pie charts and Pareto charts How to graph and interpret paired data sets using scatter plots and time series charts 1 Copyright 2019, 2015, 2012, Pearson Education, Inc. Graphing Quantitative Data Sets Stem-and-leaf plot Each number is separated into a stem and a leaf. Similar to a histogram. Still contains original data values. Provides an easy way to sort data. Data: 21, 25, 25, 26, 27, 28, 30, 36, 36, 45 26 2 1 5 5 6 7 8 3 0 6 6 4 5 . 1 Copyright 2019, 2015, 2012, Pearson Education, Inc. Example: Constructing a Stem-and-Leaf Plot The data set lists the numbers of text messages sent in one day by 50 cell phone users. Display the data in a stem-and-leaf plot. Describe any patterns. (Adapted from Pew Research) 1 Copyright 2019, 2015, 2012, Pearson Education, Inc. Solution: Constructing a Stem-and-Leaf Plot The data entries go from a low of 16 to a high of 149. Use the rightmost digit as the leaf. For instance, 76 = 7 | 6 and 149 = 14 | 9 List the stems, 7 to 14, to the left of a vertical line. For each data entry, list a leaf to the right of its stem. 1 Copyright 2019, 2015, 2012, Pearson Education, Inc. Solution: Constructing a Stem-and-Leaf Plot From the display, you can see that more than 50% of the cell phone users sent between 20 and 50 text messages. 1 Copyright 2019, 2015, 2012, Pearson Education, Inc. Example: Constructing Variations o