50 
BULLETIN 1480, U. S. DEPARTMENT OF AGRICULTURE 
cients of variability 29 and 27 per cent. These comparisons appear 
in Table 24. Figure 9 shows graphically the relationship between 
the two series of hog prices. 
Table 24. — Comparison 
of farm prices and 
market prices 
Num- 
Average of 
price series 
standard de- 
viations of series 
Coefficient of 
variability of 
Corre- 
lation 
Products, prices, and dates 
ber of 
months 
coeffi- 
cient 
Xii 
X 2 2 
Xi* 
X 2 2 
Xi» 
Xj2 
(r) 
Farm prices of Iowa hogs, and Chi- 
cago market prices: * 
Dollars 
Dollars 
Dollars 
Dollars 
Per cent 
Per cent 
Plus 
1910-1914 
60 
7.35 
8.00 
0.97 
0.99 
13 
12 
0.992 
1915-1919 
60 
12. 70 
13.60 
4.56 
4.77 
36 
35 
.998 
1920-May, 1925 
65 
8.93 
9.75 
2.55 
2.67 
29 
27 
.997 
Farm prices of Kansas wheat, and 
monthly average market prices at 
Kansas City: 
Cents 
Cents 
Cents 
Cents 
July, 1920-December, 1923 
42 
115.9 
133.2 
36.0 
41.0 
31 
31 
.990 
Farm prices of Kansas wheat, and 
average market prices at Kansas 
City, weeks ending the 15th of each 
month: 
July, 1920-December, 1923 
42 
115.9 
135.1 
36.0 
43.0 
31 
32 
.984 
Farm prices of North Dakota wheat, 
and monthly average market prices 
at Minneapolis: 
July, 1920-December, 1923 
42 
114.6 
141.3 
38.4 
37.7 
34 
27 
.987 
Farm prices of North Dakota wheat, 
and average market prices at Min- 
neapolis, weeks ending 15th of each 
month: 
July, 1920-December, 1923 
42 
114.6 
143.5 
38.4 
40.5 
34 
28 
.984 
Farm prices of Texas cotton, and 
average prices of middling cotton at 
New Orleans, 5 days ending the 
15th of each nionth: 
1910-1914 
60 
60 
12.00 
20.71 
12.89 
21.73 
1.69 
8.79 
1.85 
9.34 
14 
42 
14 
43 
.957 
1915-1919 
.991 
1920-1925 
72 
22.85 
24.64 
7.11 
7.89 
31 
32 
.979 
1910-1925 
192 
18.92 
20.19 
8.12 
8. 76 
43 
43 
.989 
1 Xi indicates the farm price series in each comparison. 
2 X2 indicates the market price series which is being compared with the farm price series. 
* Chicago market prices obtained for the weeks ending the 15th of each month by interpolating prices 
of calendar weeks. 
KANSAS AND NORTH DAKOTA WHEAT PRICES 
Prior to January, 1924, wheat prices as well as the prices of other 
important crops, were obtained on the 1st of the month instead of 
the 15th. The prices for the two consecutive dates were averaged 
to obtain a price which would be a little more comparable with prices 
as obtained on the 15th. This method of averaging two prices tends 
to lessen the price change from one month to the next. 
A comparison of the Kansas farm price of wheat and the Kansas 
City cash-sale price was made for the period from July, 1920, to 
December, 1923. The correlation between the monthly average sale 
price for Kansas City (p. 629) and the Kansas farm price (the aver- 
age of the first of two consecutive months) was plus 0.990. The 
correlation between a weekly average of Kansas City cash-sale price 
for the week ending the 15th of each month (average price of all 
sales for the six-day period) and the Kansas farm prices as just de- 
scribed was plus 0.981. See Table 2-1 for a comparison of wheat 
prices. A similar study comparing North Dakota farm prices of 
wheat and the Minneapolis monthly average cash-sale prices showed 
a correlation of plus 0.987. The correlation between North Dakota 
