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BULLETIN 1480, U. ». DEPARTMENT OF AGRICULTURE 
ANALYSIS OF THE FARM-PRICE SAMPLE 
Is the State farm-price average, obtained by the method of 
sampling used by the department, representative of the great variety 
of conditions existing within an area as large as a State ? Assuming 
that the sample is fairly representative of the various price zones 
within the State, is the average of the sample reliable ? Does a drop 
in the average price of wheat for Kansas signify that wheat is selling 
for 5 cents less, or is the change in the average due to changes in the 
composition of the sample, commonly known as " fluctuations in 
sampling "? 
IOWA CORN PRICES, MAYJ926 
(Cents Per Bushel) 
Total number oF reports in State equals 184 
State price, weighted, equals £6 
* Schedule received but it contained no report on corn prices 
Fig. 4. — Distribution of reports on Iowa corn prices for May, 1926. Prices were received 
from about 80 per cent of the counties. Tbe surplus-corn counties were well repre- 
sented 
GEOGRAPHICAL REPRESENTATIVENESS OF THE SAMPLE 
Certain variations in the price of a given farm product are to be 
expected. A fully representative sample should include price reports 
from the different parts of the State where these variations occur. 
Figure 4 shows the distribution of the reports for May, 1926, on corn 
prices in the various counties of Iowa. 
Prices were received from 80 per cent of the counties. In a year 
like 1925-26, in which the corn crop was large, a much larger pro- 
portion of the counties are surplus-producing counties than in a year 
like 1924, when the corn crop was short. Also the difference between 
the prices in surplus-producing and deficit counties is much smaller 
in actual amount, but remains about the same proportion of the 
lower average price. 
More reports than were necessary were received from several of 
the counties. If the reports from half or two-thirds of the counties 
