Chapter 15A - Describing data statistically. This chapter presents the steps necessary to prepare data for data analysis. This chapter presents the following content: Frequencies, distributions, characteristics of distributions, measures of central tendency,. | Describing Data Statistically Appendix 15a McGraw-Hill/Irwin Copyright © 2014 by The McGraw-Hill Companies, Inc. All rights reserved. 1 This chapter presents the steps necessary to prepare data for data analysis. Research Thought Leader “In the future, we’ll stop moaning about the lack of perfect data and start using the good data with much more advanced analytics and data-matching techniques.” Kate Lynch research director Leo Burnett’s Starcom Media Unit Frequencies Unit Sales Increase (%) Frequency Percentage Cumulative Percentage 5 6 7 8 9 Total 1 2 3 2 1 9 100 Unit Sales Increase (%) Frequency Percentage Cumulative Percentage Origin, foreign (1) 6 7 8 1 2 2 Origin, foreign (2) 5 6 7 9 Total 1 1 1 1 9 A 3 This chapter begins with a review of critical concepts from statistics courses. Exhibit 15a-1 provides an example of frequencies and distributions based | Describing Data Statistically Appendix 15a McGraw-Hill/Irwin Copyright © 2014 by The McGraw-Hill Companies, Inc. All rights reserved. 1 This chapter presents the steps necessary to prepare data for data analysis. Research Thought Leader “In the future, we’ll stop moaning about the lack of perfect data and start using the good data with much more advanced analytics and data-matching techniques.” Kate Lynch research director Leo Burnett’s Starcom Media Unit Frequencies Unit Sales Increase (%) Frequency Percentage Cumulative Percentage 5 6 7 8 9 Total 1 2 3 2 1 9 100 Unit Sales Increase (%) Frequency Percentage Cumulative Percentage Origin, foreign (1) 6 7 8 1 2 2 Origin, foreign (2) 5 6 7 9 Total 1 1 1 1 9 A 3 This chapter begins with a review of critical concepts from statistics courses. Exhibit 15a-1 provides an example of frequencies and distributions based on sales of LCD TVs. A frequency table arrays category codes from lowest value to highest value, with columns for count, percent, percent adjusted for missing values, and cumulative percent. A frequency distribution is an ordered array of all values for a variable. The table arrays data by assigned numerical value, in this case the actual percentage unit sales increase recorded. To discover how many manufacturers were in each unit sales increase category, read the frequency column. The cumulative percentage reveals the number of manufacturers that provided a response and any others that preceded it in the table. This column is helpful when the data have an underlying order. The proportion is the percentage of elements in the distribution that a criterion. In the example, the criterion is the origin of manufacture. Distributions 4 In Exhibit 15a-2, shown in the slide, the bell-shaped curve that is superimposed on the distribution of annual unit sales increases for LCD TV manufacturers .
