Commodity
Flow Survey
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SAMPLE SELECTION CALCULATOR
To assist you with selecting the sample of your shipments to report in Item F, complete the item below:
Enter the total number of outbound shipments reported in Item D, page 2, of the survey form -
SAMPLING INSTRUCTIONS
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Find the range in column (1)
of the table below that contains the number of shipments you reported
in Item D.
Expanded Table for Determining Selection Rate
(1)
Number of Shipments Reported in Item D |
(2)
Selection Rate |
(3)
Number of Shipments that Should be Reported in Item F |
1 - 40 |
Every shipment |
1 - 40 |
41 - 80 |
2 |
20 - 40 |
81 - 100 |
3 |
27 - 33 |
101 - 200 |
5 |
20 - 40 |
201 - 400 |
10 |
20 - 40 |
401 - 800 |
20 |
20 - 40 |
801 - 1,600 |
40 |
20 - 40 |
1,601 - 3,200 |
80 |
20 - 40 |
3,201 - 6,400 |
160 |
20 - 40 |
6,401 - 12,800 |
320 |
20 - 40 |
12,801 - 25,600 |
640 |
20 - 40 |
25,601 - 51,200 |
1,280 |
20 - 40 |
51,201 - 102,400 |
2,560 |
20 - 40 |
102,401 - 204,800 |
5,120 |
20 - 40 |
204,801 - 409,600 |
10,240 |
20 - 40 |
409,601 - 819,200 |
20,480 |
20 - 40 |
-
Find the selection rate, as given
in column (2) of the table, that corresponds to the range
you identified in the previous step.
-
Determine the number of shipments you should report
for in Item F by dividing the number you reported in Item D by
the selection rate and dropping the remainder. For example, if
Item D is 349, then the corresponding range from column (1) is
201-400 and the selection rate is 10. Dividing 349 by 10 and dropping
the remainder gives 34. Therefore, you should report for a sample
of 34 shipments.
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Source: U.S. Census Bureau, Service
Sector Statistics Division,
Commodity Flow Branch
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