12 



.75 :.as : : X : 500 

 25 X = 375 

 X = 1 500 pounds of 23% cream. 



The following problem is an illustration of the original method 

 of working standardization problems when a definite amount of the 

 mixture is desired. 

 Problem 4. 



How much 23% cream and 3% milk must be mixed to make a 

 cream testing 18%? Since the percentages of fat in these problems 

 are the same as those in Problem 3, the amount of 3% milk in one 

 pound of an 18% mixture would be the same as already shown, and 

 therefore needs no further explanation. Since .25 is the number of 

 pounds of 3% milk in one pound of 18% cream, we would have the 

 simple proportion: 

 i:.25 :: 500 : X 



X = 125, the number of pounds of 3% milk in an 18% mixture. 

 The remainder of the mixture, 375 pounds (500 125), will be 23% 

 cream. The cream could, of course, be found by forming the follow- 

 ing simple proportion. 

 11.75 :: 500 : X 



X = 375 pounds of 23% cream. 



NOTE: In the two following exercises on Standardization it is 

 intended that one shall consist of a problem where the amount to 

 be standardized is definite and the other shall be a problem where the 

 resulting amount is indefinite. 



EXERCISE II 

 STANDARDIZING 



1. Test for fat by the Babcock method the samples of milk and 

 cream to be used in standardization. Report the percentages of 

 fat found and a definite percentage to which the milk or cream is to 

 be standardized will be assigned. 



2. After standardizing the milk or cream as directed, test it for 

 fat by the Babcock method in order to verify the accuracy of 

 work. 



