3.3 Graphical Method
3.3 Graphical Method
Presenting data using the graphical method facilitates the easy comparison and interpretation of data without having to go through numerical data.
Types of Charts:
Bar Chart - represented by either vertical or horizontal rectangles whose bases represent the class intervals and whose heights represent frequencies
Examples: {Click on image to see full-sized chart.}
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Histogram - represented by either vertical or horizontal rectangles whose basesare the class marks and whose heights are the frequencies
Example: {Click on image to see full-sized chart.}
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Frequency Polygon - line graph whose bases are the class marks and whose heights are the frequencies
Example: {Click on image to see full-sized chart.}
note:additional points at both ends of the graph are added to close of the ends
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Pie Chart - circle graph showing the proportion of each class through the relative or percentage frequency
Example: {Click on image to see full-sized chart.}
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Ogive Chart - line graph where the bases are the class boundaries and the heights are the < cf for the less than Ogive and the > cf for the greater than Ogive
Example: {Click on image to see full-sized chart.}
note:the < cf are plotted against the upper boundaries and the height for the first cb (lower cb of the first class) is 0; the > cf are plotted against the lower boundaries and the height for the last cb (upper cb of the last class) is 0