CHAPTER 2 Technology Project 83 In Exercises 1–5, use the data listed in the margin, which are magnitudes (Richter scale) and depths (km) of earthquakes from Data Set 24 “Earthquakes” in Appendix B. 1.Frequency Distribution Construct a frequency distribution of the magnitudes. Use a class width of 0.50 and use a starting value of 1.00. 2. Frequency Distribution For the frequency distribution from Exercise 1, find the following. a. Class limits of the first class b. Class boundaries of the first class c. Class midpoint of the first class 3. Histogram Construct the histogram corresponding to the frequency distribution from Exercise 1. For the values on the horizontal axis, use the class midpoint values. Which of the following comes closest to describing the distribution: uniform, normal, skewed left, skewed right? 4.Data Type a. The listed earthquake depths (km) are all rounded to one decimal place. Before rounding, are the exact depths discrete data or continuous data? b. For the listed earthquake depths, are the data categorical or quantitative? c. Identify the level of measurement of the listed earthquake depths: nominal, ordinal, interval, or ratio. d. Given that the listed earthquake depths are part of a larger collection of depths, do the data constitute a sample or a population? 5.Correlation Between Magnitudes and Depths Using the paired magnitude>depth data, construct the graph that is helpful in determining whether there is a correlation between earthquake magnitudes and depths. Based on the result, does there appear to be a correlation? Cumulative Review Exercises Magnitude Depth (km) 2.45 0.7 3.62 6.0 3.06 7.0 3.30 5.4 1.09 0.5 3.10 0.0 2.99 7.0 2.58 17.6 2.44 7.0 2.91 15.9 3.38 11.7 2.83 7.0 2.44 7.0 2.56 6.9 2.79 17.3 2.18 7.0 3.01 7.0 2.71 7.0 2.44 8.1 1.64 7.0 Technology Project Graphs It was stated in this chapter that the days of charming and primitive hand-drawn graphs are well behind us, and technology now provides us with powerful tools for generating a wide variety of different graphs. This project therefore serves as a good preparation for professional presentations that will be inevitably made in the future. The complete data sets in Appendix B are already included in Statdisk. Also, those data sets can be downloaded from www.TriolaStats.com. They can be opened by statistical software packages, such as Minitab, Excel, SPSS, and JMP. Use a statistical software package to open Data Set 1 “Body Data.” Use this software with the methods of this chapter to explore and compare the pulse rates of females and the pulse rates of males. • Obtain a printed copy of the two histograms. In both cases, use a class width of 10 beats per minute and use 30 beats per minute as the lower class limit of the first class. • Describe the natures of the two distributions (uniform, normal, skewed left, skewed right), and identify possible outliers. continued
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