27O MODERN METHODS OF TESTING MILK 



21. CHANGING QUARTS OF MILK INTO POUNDS 



Rule. Multiply the number of quarts by 2.15. Ex- 

 ample : How many pounds in 40 quarts of milk ? 40 

 X2.i5=86 pounds. 



22. CHANGING DEGREES FAHRENHEIT INTO 

 DEGREES CENTIGRADE 



Rule. From the degrees F. subtract 32 and mul- 

 tiply the result by 5-9. Example: 162 F.=(i62 32) 

 x 5 - 9 =72 C. 



23. CHANGING DEGREES CENTIGRADE INTO 

 DEGREES FAHRENHEIT 



Rule. Multiply the degrees C. by 9-5 and add 32. 

 Example: 72 C.= (72X9-5)+32=i62 F. 



24. FINDING THE TRUE AVERAGE 



Rule. To find the true average per cent, of fat in 

 different lots of milk or milk products, Und the weight 

 of fat in each separate lot by Rule i, add these amounts 

 and divide the sum by the total weight of milk or milk 

 products. Example: What is the average per cent, 

 of fat in the following lots of milk ? 



Pounds Per cent* Pounds 



of milk of fat of fat 



400 containing 4.3 17.2 



300 34 io.2l 



800 5.2 41.6 



100 3.1 3-i 



i, 600 



