To add meaning to numerical values, a comparison with index numbers is often useful.

The insertion of the small index number chart in the space at the upper right shows one method of accomplishing this.

2. Note the method of breaking the grid to indicate an omission of a period of years.

3. See 93 A4.

GRAPHIC PRESENTATION

WPA. and Burrau of Acncultural Economics. "Rural Poverty." l')38. A. Trends of Expenditures for Relief in the United States fronn 1932 to December 1936.

When a broad line is used for a curve, the point in the middle of the line is the plotted point. If great accuracy is desired, a thin line should be used. The advantage of a thick line is that it is easily seen from a distance.

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B. Steel Production in the United States from 1921 to 1938. 1926 Equals 100%.

This chart shows concretely that the average for the base period actually averages 100% on the chart. Sec also 302B.

INDEX NUMBERS SHOWN BY CURVES

MOCX NUMBint, HI6H MONTH Of i«s;>ioo

National Industrial Confrrcnoc Board. Inc , November 2S. 1038 Depression and Recovery in the United States for the Years 1937 and 1938.