6 BULLETIN 1006, U. S. DEPARTMENT OF AGRICULTURE. 



COMPUTING THE GRADE AND SIZE GROUP WEIGHTS. 



It is the duty of the office clerk in charge of receipts to ascertain 

 what percentage the fruit in the sample is of the total fruit on the 

 load and to compute the weights of the various grades and sizes. 

 This percentage is found by dividing the total net weight of the 

 sample by the net weight of the fruit on the load. For example : 



Assume that 163.2 pounds is the net weight of the whole sample 

 and that 4,000 pounds is the net weight of the load of fruit. To 

 determine the percentage of test: 163.2- divided by 4,000 equals 

 4.08 per cent. 



Having determined the percentage of test, it is a comparatively 

 simple matter to compute the total weight of each grade and size in 

 the lot from the results of the test, as reported by the test clerk 

 under "Test weights" on the sampled-fruit receipt. This can be 

 done either by dividing the test weights by the percentage of test, 

 or by multiplying the test weight by the reciprocal of the percentage 

 of test, as shown in the table on page 9. 



Now, the percentage of test is 4.08 per cent. Suppose that the 

 Extra Fancy (36-125) test weight is 50.2 pounds; Fancy (36-125) 

 test w T eight, 75.6 pounds; "C" grade (36-163) test weight, 37.4 pounds. 

 To compute the weights of the various grades in this size group by 

 the percentage division method: 



Test weights. Total weights. 



Extra Fancy (36-125) 50. 2 pounds divided by 0.0408 equals 1, 230. 40 pounds. 



Fancy (36-125) 75. 6 pounds divided by 0.0408 equals 1, 852. 94 pounds. 



" C " (36-163) 37. 4 pounds divided by 0.0408 equals 916. 66 pounds. 



Total 163. 2 pounds 4, 000. pounds. 



(In this method the percentage is expressed as hundredths, i. e., 

 0.04 is used instead of 4 per cent, hence there can never be less than 

 two decimal places in the divisor.) 



To determine the weights by the reciprocal-multiplier method: 

 The reciprocal of 4.08 per cent test is 24.51 (see Table of reciprocals, 

 p. 9). 



Test weights. Total weights. 



Extra Fancy (36-125) 50. 2 pounds times 24. 51 equals 1, 230. 40 pounds. 



Fancy (36-125) 75. 6 pounds times 24. 51 equals 1, 852. 94 pounds. 



" C " (36-163) 37. 4 pounds times 24. 51 equals 916. 66 pounds. 



Total 163. 2 pounds • 4, 000. 00 pounds. 



To facilitate the above computations the reciprocals are carried 

 out only two decimal places and the last digit of the total weight is 

 corrected as a means of obtaining a balance. 



REGISTERING THE SAMPLED-FRUIT RECEIPTS. 



The weights of the various grade and size groups appearing on the 

 sampled-fruit receipts are entered daily on the register of sampled- 



