39 Where You’re Going In Chapter 2, you will learn ways to organize and describe data sets.The goal is to make the data easier to understand by describing trends, averages, and variations. For instance, in the raw data showing the points scored by the winning teams in the first 55 Super Bowls, it is not easy to see any patterns or special characteristics. Here are some ways you can organize and describe the data. Where You’ve Been In Chapter 1, you learned that there are many ways to collect data. Usually, researchers must work with sample data in order to analyze populations, but occasionally it is possible to collect all the data for a given population. For instance, the data at the right represent the points scored by the winning teams in the first 55 Super Bowls. (Source: ESPN.com) 35, 33, 16, 23, 16, 24, 14, 24, 16, 21, 32, 27, 35, 31, 27, 26, 27, 38, 38, 46, 39, 42, 20, 55, 20, 37, 52, 30, 49, 27, 35, 31, 34, 23, 34, 20, 48, 32, 24, 21, 29, 17, 27, 31, 31, 21, 34, 43, 28, 24, 34, 41, 13, 31, 31 Mean = 35 + 33 + 16 + 23 + 16 + . . . + 41 + 13 + 31 + 31 55 = 1657 55 ≈ 30.1 points Range = 55 - 13 = 42 points Find an average. Find how the data vary. Make a frequency distribution. Class Frequency, f 13 –19 6 20 – 26 13 27 – 33 17 34 – 40 11 41 – 47 4 48 – 54 3 55 –61 1 Draw a histogram. 2 12.5 19.5 26.5 33.5 40.5 47.5 54.5 61.5 4 6 8 10 14 16 18 12 Points Frequency
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