GRAPHIC PRESENTATION

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Brinton, "Graphic Methods." McGraw-Hill, 1914.

SCALE .5

A. Yearly Average of Revenue Tons per Train Mile on the Pittsburgh and Lake Erie Railroad.

1. The dotted line in this chart is a progressive average, or an average of all the items

shown.

2. The numbers along the top of the chart give the value of the points on the plotted

curves.

3. When space does not allow the dates to be put in full, the method shown here identifies

each vertical line, and accents the decades.

4. Note the position of the scale designation in the upper left corner for both the scale and

data figures.

U. S. Department of ARriculture, Bureau of Agricultural Economics. SCALE .8

B. Annual Yield and Nine-Year Moving Average Yield of Rye Per Acre in the United States from 1 866 to 1930.

A moving average, often used in graphic charts, is obtained in this way: the statistics for a number of years are averaged and the result is plotted at the half-way mark. Thus if the data for the 9 years from 1890 to 1898 had been averaged, the result would be plotted at the year 1895.

COMPARISONS WITH CURVES

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