Page:Graphic methods for presenting facts (1914).djvu/118

 ''Elements of Statistics, by A. L. Bowley. P. S. King & Son, London''

Fig. 91. Total Value of British and Irish Produce Exported from the United Kingdom, 1855-1906

The fine dotted line shows a curve plotted from yearly averages. This line fluctuates in such manner that it is difficult to tell the general tendency of the exports under consideration. Other curves are drawn from the same data but using moving averages of three, five, and ten years to show the effect in "smoothing" the curve. The heavy line is drawn through points which represent the average for each of the different decades, and it is smoothed arbitrarily to give the best representation of the trend of exports[No period consistent with other Figs. P2

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