Page:Graphic methods for presenting facts (1914).djvu/201

 Fig. 155. Chart Showing What Percentage of the Wage Earners in Different Portions of the United States Receive More than any Specified Amount of Earnings up to Twenty-Five Dollars per Week

Here the scales are correctly arranged so that the two zeros appear at the lower left-hand corner. The plotting of these curves on a "more than" basis causes curves which show the largest earnings to appear in their proper position toward the top of the chart. Plotting of cumulative frequency curves on a "more than" basis is usually desirable, since it reduces the chances for confusion to the reader. This chart could have been improved if the words "more than" and an arrow had been placed at the lower left-hand corner on the general scheme of Fig. 158

In Fig. 156 we have cumulative frequency curves applied to a comparison of wages in different departments of a corporation. Here again the words "more than" and the arrow would have been desirable at the lower left-hand corner of the chart. The general position of the curves beginning at the upper left-hand corner, however, assists the reader to see that these curves are plotted on a "more than" basis. A chart of this kind is of great utility in making a study of wages. It may be noticed, for instance, in the curve for laborers, that there is a very decided change in the shape of the curve at about $9.00 per week. Only 62 per cent of these laborers make more than $9.00 per week and but 80 per cent of them get more than $5.00 per