CHAPTER 12 Summary 837 Important Facts and Concepts Examples and Discussion Section 12.1 Sampling Techniques Random sampling Systematic sampling Cluster sampling Stratified sampling Convenience sampling Misuses of statistics Example 1, page 764 Discussion, pages 764–766 Section 12.2 Frequency distribution Rules for Data Grouped by Classes 1. The classes should be the same width. 2. The classes should not overlap. 3. Each piece of data should belong to only one class. In addition, there should be between 5 and 12 classes, inclusive. Statistical Graphs Histogram Frequency polygon Stem-and-leaf display Circle graph Examples 1–3, pages 771–774 Discussion, page 771; Examples 2–3, pages 772–774 Examples 4, 6, 7, pages 774–777 Examples 5– 6, pages 775–776 Example 8, pages 777–778 Example 9, page 779 Summary CHAPTER 12 Use this formula to determine the correlation coefficient of the set of bivariate data given in Example 1. 0.922 ≈ a) Compare your answer with the answer obtained in Example 1. Should be the same. Research Activities 50. Bivariate Data a) Obtain a set of bivariate data from a newspaper, magazine, or the Internet. b) Plot the information on a scatter diagram. c) Indicate whether you believe that the data show a positive correlation, a negative correlation, or no correlation. Explain your answer. d) Calculate r and determine whether your answer to part (c) was correct. e) Determine the equation of the line of best fit for the bivariate data. 51. Scatter Diagram Find a scatter diagram in a newspaper, magazine, or the Internet and write a paper on what the diagram indicates. Indicate whether you believe that the bivariate data show a positive correlation, a negative correlation, or no correlation and explain why.
RkJQdWJsaXNoZXIy NjM5ODQ=