Pom Cases

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  • Topic: Frequency distribution, Harshad number, Histogram
  • Pages : 18 (2232 words )
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  • Published : April 27, 2013
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Chapter 2
Charts and Graphs


The overall objective of chapter 2 is for you to master several techniques for summarizing and depicting data, thereby enabling you to:

1.Recognize the difference between grouped and ungrouped data.

2.Construct a frequency distribution.

3.Construct a histogram, a frequency polygon, an ogive, a pie chart, a stem and leaf plot, a Pareto chart, and a scatter plot.


Chapter 1 brought to the attention of students the wide variety and amount of data available in the world of business. In chapter 2, we confront the problem of trying to begin to summarize and present the data in a meaningful manner. One mechanism for data summarization is the frequency distribution which is essentially a way of organizing ungrouped or raw data into grouped data. It is important to realize that there is considerable art involved in constructing a frequency distribution. There are nearly as many possible frequency distributions for a problem as there are students in a class. Students should begin to think about the receiver or user of their statistical product. For example, what class widths and class endpoints would be most familiar and meaningful to the end user of the distribution? How can the data best be communicated and summarized using the frequency distribution?

The second part of chapter 2 presents various ways to depict data using graphs. The student should view these graphical techniques as tools for use in communicating characteristics of the data in an effective manner. Most business students will have some type of management opportunity in their field before their career ends. The ability to make effective presentations and communicate their ideas in succinct, clear ways is an asset. Through the use of graphics packages and such techniques as frequency polygons, ogives, histograms, and pie charts, the manager can enhance his/her personal image as a communicator and decision-maker. In addition, emphasize that the final product (the frequency polygon, etc.) is just the beginning. Students should be encouraged to study the graphical output to recognize business trends, highs, lows, etc. and realize that the ultimate goal for these tools is their usage in decision making.


2.1Frequency Distributions
Class Midpoint
Relative Frequency
Cumulative Frequency

2.2Graphic Depiction of Data
Frequency Polygons
Pie Charts
Stem and Leaf Plots
Pareto Charts

2.3 Graphical Depiction of Two-Variable Numerical Data: Scatter Plots


Class MarkPareto Chart
Class Midpoint Pie Chart
Cumulative Frequency Range
Frequency DistributionRelative Frequency
Frequency Polygon Scatter Plot
Grouped Data Stem and Leaf Plot
HistogramUngrouped Data


a)One possible 5 class frequency distribution:

Class IntervalFrequency
10 - under 25 9
25 - under 40 13
40 - under 55 11
55 - under 70 9
70 - under 85 8

b)One possible 10 class frequency distribution:

Class IntervalFrequency
10 - under 18 7
18 - under 26 3
26 - under 34 5
34 - under 42 9
42 - under 50 7
50 - under 58 3
58 - under 66 6
66 - under 74 4
74 - under 82 4
82 - under 90 2

c)The ten class frequency distribution gives a more detailed breakdown of temperatures, pointing out the smaller frequencies for the higher temperature intervals. The five class distribution collapses the intervals into broader classes making it...
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