Table B-4a. Estimated Measures of Reliability for Shipment Characteristics by Shipment Weight: 2002
Monday, July 2, 2012
Table B-4a. Estimated Measures of Reliability for Shipment Characteristics by Shipment Weight: 2002
[Estimates are shown as percents and are based on data from the 2002 Commodity Flow Survey]
| Shipment Weight | Value | Tons | Ton-miles | Average miles per shipment- coefficient of variation | |||
|---|---|---|---|---|---|---|---|
| Coefficient of variation of number | Standard error of percent | Coefficient of variation of number | Standard error of percent | Coefficient of variation of number | Standard error of percent | ||
| All shipment sizes | 1.3 | – | 2.0 | – | 3.7 | – | 2.9 |
| Less than 50 lbs | 2.5 | 0.3 | 2.7 | – | 3.5 | – | 2.8 |
| 50 to 99 lbs | 5.6 | 0.2 | 4.7 | – | 6.8 | – | 5.4 |
| 100 to 499 lbs | 3.0 | 0.3 | 3.4 | – | 2.6 | – | 3.5 |
| 500 to 749 lbs | 3.3 | 0.1 | 3.3 | – | 2.8 | – | 3.3 |
| 750 to 999 lbs | 3.8 | – | 4.6 | – | 2.6 | – | 4.4 |
| 1,000 to 9,999 lbs | 2.6 | 0.3 | 1.9 | 0.1 | 3.7 | 0.2 | 2.8 |
| 10,000 to 49,999 lbs | 1.7 | 0.5 | 3.3 | 0.8 | 2.1 | 0.9 | 2.7 |
| 50,000 to 99,999 lbs | 3.6 | 0.2 | 3.8 | 0.5 | 4.6 | 0.3 | 4.5 |
| 100,000 lbs or more | 6.5 | 0.5 | 3.4 | 1.0 | 6.2 | 1.3 | 3.2 |
KEY:
– Represents data cell equal to zero or less than 1 unit of measure.
S Estimate does not meet publication standards because of high sampling variability or poor response quality.
NOTE: The Introduction and appendixes give information onf confidentiality protection, sampling error, nonsampling error, sample design, and definitions. Links to this information on the Internet may be found at www.census.gov/cfs.
SOURCE: Bureau of Transportation Statistics (USDOT) and U.S. Census Bureau, 2002 Commodity Flow Survey, United States Data, December 2004.