Chapter 2.2（课件）- 《统计学基础（英文）》同步教学（人民大学·第7版）

Elementary Statistics Seventh Edition Chapter 2 Descriptive Statistics Copyright 2019, 2015, 2012, Pearson Education, Inc. Slide 1 Slide ‹#› If this PowerPoint presentation contains mathematical equations, you may need to check that your computer has the following installed: 1) MathType Plugin 2) Math Player (free versions available) 3) NVDA Reader (free versions available) 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 Copyright 2019, 2015, 2012, Pearson Education, Inc. Slide ‹#› 2 Section 2.2 More Graphs and Displays Slide ‹#› Copyright 2019, 2015, 2012, Pearson Education, Inc. Slide ‹#› 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 Copyright 2019, 2015, 2012, Pearson Education, Inc. Slide ‹#› 4 Graphing Quantitative Data Sets (1 of 2) 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 Copyright 2019, 2015, 2012, Pearson Education, Inc. Slide ‹#› 5 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) Number of Text Messages Sent 76 49 102 58 88 122 76 89 67 80 66 80 78 69 56 76 115 99 72 19 41 86 48 52 28 26 29 33 26 20 33 24 43 16 39 29 32 29 29 40 23 33 30 41 33 38 34 53 30 149 Copyright 2019, 2015, 2012, Pearson Education, Inc. Slide ‹#› 6 Solution: Constructing a Stem-and-Leaf Plot (1 of 2) The data entries go from a low of 16 to a high of 149. Use the rightmost digit as