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- 2. Learning Objectives Overall: To give students a basic understanding of best way of presentation of data
- 3. 2. Descriptive statistics involves arranging, summarizing, and presenting a set of data in such a way
- 4. DATA MINING Most companies routinely collect data – at the cash register for each purchase, on
- 5. DATA MINING is a collection of methods for obtaining useful knowledge by analyzing large amounts of
- 6. 1. Marketing and sales: companies have lots of information about past contacts with potential customers and
- 7. Finance: Mining of financial data can be useful in forming and evaluating investment strategies and in
- 8. Statistical methods, such as hypothesis testing, are helpful as part of data mining distinguish random from
- 9. 3. Product design: What particular combinations of features are customers ordering in larger-than-expected quantities? The answers
- 10. 4. Production Imagine a factory running 24/7 with thousands of partially completed units, each with its
- 11. 5. Fraud detections: Fraud can affect many areas of business, including consumer finance, insurance, and networks
- 12. YOU once received a telephone call from your credit card company asking you to verify recent
- 13. Data mining is a large task that involves combining resources from many fields. Here is how
- 14. Statistics: All of the basic activities of statistics are involved: a design for collecting the data,
- 15. Some specialized statistical methods are particularly useful, including classification analysis (also called discriminant analysis) to assign
- 16. Computer science: Efficient algorithms (computer instructions) are needed for collecting, maintaining, organizing, and analyzing data. Creative
- 17. Optimization: These methods help you achieve a goal, which might be very specific such as maximizing
- 18. Alternatively, the goal might be more vague such as obtaining a better understanding of the different
- 19. WHAT IS PROBABILITY? Probability is a what if tool for understanding risk and uncertainty. Probability shows
- 20. You might learn, for example, that an international project has only an 8% chance of success
- 21. Here are additional examples of situations where finding the appropriate answer requires computing or estimating a
- 22. 3. What are the chances that a foreign country (where you have a manufacturing plant) will
- 23. Probability is the inverse of statistics. Whereas statistics helps you go from observed data to generalizations
- 24. Probability also works together with statistics by providing a solid foundation for statistical inference. When there
- 26. 2. Definitions… A variable [Typically called a “random” variable since we do not know it’s value
- 27. 2. We Deal with “2” Types of Data Numerical/Quantitative Data [Real Numbers]: * height * weight
- 28. 2. Quantitative/Numerical Data… Quantitative Data is further broken down into Continuous Data – Data can be
- 29. 2. Qualitative/Categorical Data Nominal Data [has no natural order to the values]. E.g. responses to questions
- 30. 2. Graphical & Tabular Techniques for Nominal Data… The only allowable calculation on nominal data is
- 31. 2. Nominal Data (Tabular Summary) -
- 32. 2. Nominal Data (Frequency) Bar Charts are often used to display frequencies… Is there a better
- 33. 2. Nominal Data (Relative Frequency) Pie Charts show relative frequencies…
- 34. Frequency Distributions Definition A frequency distribution for qualitative data lists all categories and the number of
- 35. Example 2.2 A sample of 30 employees from large companies was selected, and these employees were
- 36. Example 2.2 Construct a frequency distribution table for these data.
- 37. Solution 2.2 Table 2.2 Frequency Distribution of Stress on Job
- 38. Relative Frequency and Percentage Distributions Calculating Relative Frequency of a Category
- 39. Relative Frequency and Percentage Distributions cont. Calculating Percentage Percentage = = (Relative frequency) · 100
- 40. Example 2.3 Determine the relative frequency and percentage for the data in Table 2.4.
- 41. Solution 2-2 Table 2.3 Relative Frequency and Percentage Distributions of Stress on Job
- 42. Graphical Presentation of Qualitative Data Definition A graph made of bars whose heights represent the frequencies
- 43. Figure 2.2 Bar graph for the frequency distribution of Table 2.3
- 44. Graphical Presentation of Qualitative Data cont. Definition A circle divided into portions that represent the relative
- 45. Table 2.4 Calculating Angle Sizes for the Pie Chart
- 46. Figure 2.4 Pie chart for the percentage distribution of Table 2.5.
- 47. ORGANIZING AND GRAPHING QUANTITATIVE DATA Frequency Distributions Constructing Frequency Distribution Tables Relative and Percentage Distributions Graphing
- 48. Frequency Distributions Table 2.7 Weekly Earnings of 100 Employees of a Company Variable Third class Lower
- 49. Frequency Distributions cont. Definition A frequency distribution for quantitative data lists all the classes and the
- 50. Essential Question : How do we construct a frequency distribution table?
- 51. Process of Constructing a Frequency Table STEP 1: Determine the range. R = Highest Value –
- 52. STEP 2. Determine the tentative number of classes (k) k = 1 + 3.322 log N
- 53. STEP 3. Find the class width by dividing the range by the number of classes. (Always
- 54. STEP 4. Write the classes or categories starting with the lowest score. Stop when the class
- 55. STEP 5. Determine the frequency for each class by referring to the tally columns and present
- 56. When constructing frequency tables, the following guidelines should be followed. The classes must be mutually exclusive.
- 57. 3. All classes should have the same width, although it is sometimes impossible to avoid open
- 58. Let’s Try!!! Time magazine collected information on all 464 people who died from gunfire in the
- 59. 19 18 30 40 41 33 73 25 23 25 21 33 65 17 20 76
- 60. Determine the range. R = Highest Value – Lowest Value R = 76 – 16 =
- 61. Determine the tentative number of classes (K). K = 1 + 3. 322 log N =
- 62. Find the class width (c). * Round – off the quotient if the decimal part exceeds
- 63. Write the classes starting with lowest score.
- 64. Using Table: What is the lower class limit of the highest class? Upper class limit of
- 66. Example Table 2.9 gives the total home runs hit by all players of each of the
- 67. Table 2.9 Home Runs Hit by Major League Baseball Teams During the 2012 Season
- 68. Solution 2-3 Now we round this approximate width to a convenient number – say, 22.
- 69. Solution 2-3 The lower limit of the first class can be taken as 124 or any
- 70. Table 2.10 Frequency Distribution for the Data of Table 2.9
- 71. Relative Frequency and Percentage Distributions Relative Frequency and Percentage Distributions
- 72. Example 2-4 Calculate the relative frequencies and percentages for Table 2.10
- 73. Solution 2-4 Table 2.11 Relative Frequency and Percentage Distributions for Table 2.10
- 74. Graphing Grouped Data Definition A histogram is a graph in which classes are marked on the
- 75. Figure 2.3 Frequency histogram for Table 2.10. 124 - 145 146 - 167 168 - 189
- 76. Figure 2.4 Relative frequency histogram for Table 2.10. 124 - 145 146 - 167 168 -
- 77. Graphing Grouped Data cont. Definition A graph formed by joining the midpoints of the tops of
- 78. Figure 2.5 Frequency polygon for Table 2.10. 124 - 145 146 - 167 168 - 189
- 79. Figure 2.6 Frequency Distribution curve Frequency x
- 80. Example 2-5 The following data give the average travel time from home to work (in minutes)
- 81. Example 2-5 Construct a frequency distribution table. Calculate the relative frequencies and percentages for all classes.
- 82. Solution 2-5
- 83. Solution 2-5 Table 2.12 Frequency, Relative Frequency, and Percentage Distributions of Average Travel Time to Work
- 84. Example 2-6 The administration in a large city wanted to know the distribution of vehicles owned
- 85. Solution 2-6 Table 2.13 Frequency Distribution of Vehicles Owned
- 86. Figure 2.7 Bar graph for Table 2.13.
- 87. Ogive The ogive is a graph that represents the cumulative frequencies for the classes in a
- 88. Ogive
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