
WEIGHT VARIATION OF PACKAGE FOODS. 
TABLE 13.—Calculated chance of occurrence of variations of different machines. 
Chance of occurrence of 
variations greater than 
0.106 ounce on _ the 
average weight. 
Make of 
machine. 

COOWhe 
— 
lon 
B 
—" 
~J 
TaBLE 14.—Recalculated chance of occurrence of variations of different machines. 

Chance:of occurrence of 
variations greater than 
0.213 ounce on single 
packages. 
lin 18 
lin 4.5 
lin 83 
lin1ll 
mies 



Chance of occurrence of | Chance of occurrence of 
Make of variations greater than variations greater than 
machine.| 0.106 ounce on _ the 0.213 ounce on single 
average weight. packages. 
1 1in more than 10,000 1 in more than 10,000 
2 lin 24 lin 11 
3 lin 5,000 lin 500 
6 lin 500 lin 83 
8 lin 38 lin 15 

PRACTICAL APPLICATION OF EXPERIMENTAL RESULTS. 
The figures in the last two columns of Tables 5 and 6, ‘‘Calculated 
maximum error on a single package”’ and “Calculated maximum 
error on the average of a representative sample,’ are of practical 
interest to the food official and the food packer. They represent the 
limiting variations in weight given in this bulletin which result from 
the use of the specified good commercial practice. Since in actual 
practice the method of packing can not always be studied carefully, 
the results of check weighings must necessarily be used to determine 
whether or not the method in use is a good one or is accurately 
operated. 
When the variation in the weight of packages of granular, free- 
flowing products, such as coffee, spices, sugar, or rice, from the 
intended weight or aim is greater than the calculated errors 
given in the tables, it can be inferred that the packages were not 
packed by as good a method as that outlined in this bulletin as good 
commercial practice (p. 3). 
For making comparisons, weights should be taken net on 50 freshly 
packed packages and the variations from the aim should be used. 
When food packers desire to check the efficiency of a method of 
packing, factory studies must be made to determine the aim. 
When food officials desire to determine whether short weighing is 
being practiced, the declared weight must necessarily be used as 
the aim, since that is the figure which is being checked. If other 
than freshly packed packages are weighed, allowance must be made 
for shrinkage. 
