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Example: Ages of wealthiest people Notes Frequency distribution table: Ages of 50 Wealthiest People (2009) Class Class Boundaries 35 - 41 34.5 - 41.5 42 - 48 41.5 - 48.5 49 - 55 48.5 - 55.5 56 - 62 55.5 - 62.5 63 - 69 62.5 - 69.5 70 - 76 69.5 - 76.5 77 - 83 76.5 - 83.5 84 - 90 83.5 - 90.5 2.1: Histogram 2.1: Relative Frequency Histogram Frequency, f 2 5 7 7 10 5 8 6 Notes Notes 2.1: Histograms I Create a column of class boundaries on the frequency distribution table. I Start and end class boundaries by subtracting a value from the lower limits (like 0.5 for whole numbers, 0.05 for data in tenths place, etc...) I Draw a horizontal line for the data entries number line. I Draw a vertical line for the frequencies of the data. I Plot consecutive bars for each class and frequency. Notes For relative frequency histograms, scale the vertical line by relative frequencies, not frequencies. 2.1: Ogive Example 2.1: Ogives Graph a cumulative frequency. I Draw a horizontal scale of upper-class boundaries. I Draw a vertical scale measuring cumulative frequencies. I Plot points as a pair for each class: (x, y ) = (upper-class boundary, cumulative frequency) I Connect the points in order with straight segments. The graph should start at the lower boundary of the first class, where the cumulative frequency is zero. It should end at the upper boundary of the last class, where the cumulative frequency is the size of the data set. Notes Notes 2.2: Stem-and-Leaf Example Notes Key: 3|5 = 35 3 4 5 6 7 8 | | | | | | 56 234679 1133446789 0113455667899 23336788 01233566799 A stem is the entry’s left-most digits, a leaf is the right-most digit. These are similar to histograms, but graph still contains all the data values. What is a disadvatage? 2.2: Dot Plot Example Notes Qualitative Data Notes Qualitative Data: Number of degrees conferred (in thousands) for 1990. Type of Degree Associate’s Bachelor’s Master’s First Professional Doctoral Number (thousands) 455 1052 325 71 38 I Use a pie chart, dividing a circle in sectors to represent categories. I Use a bar chart or Parteo chart, a vertical bar graph where the height of bars are the frequencies. 2.2: Pie Chart Example 2.2: Pareto Chart (Bar Chart) Example Assignment For May 30: I Homework §2.1: #47, #48 (due June 2) I Homework §2.2: #36, #38, #39, #40 (due June 2) Suggested Exercises: §2.1: 2, 3, 4, 5, 35; §2.2: 2, 9, 10, 11, 12, 17, 18 You should be able to: I Construct a histogram, relative frequency histogram, and ogive. I Construct a stem-and-leaf plot, box plot, and pie charts and Pareto charts. Notes Notes Notes