Table A: [Confidence limits] 95% confidence limits for estimates, based on SHS sub-samples sizes
Table A: [Confidence limits] 95% confidence limits for estimates, based on SHS sub-samples sizes
| Sub-sample size (=100%) | Estimate | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 5% | 10% | 15% | 20% | 25% | 30% | 35% | 40% | 45% | 50% | |
| or | or | or | or | or | or | or | or | or | ||
| 95% | 90% | 85% | 80% | 75% | 70% | 65% | 60% | 55% | ||
| percentage points ( + / - ) | ||||||||||
| 100 | 5.0 | 6.8 | 8.1 | 9.1 | 9.8 | 10.4 | 10.8 | 11.1 | 11.3 | 11.4 |
| 200 | 3.5 | 4.8 | 5.7 | 6.4 | 7.0 | 7.4 | 7.7 | 7.9 | 8.0 | 8.0 |
| 300 | 2.9 | 3.9 | 4.7 | 5.3 | 5.7 | 6.0 | 6.3 | 6.4 | 6.5 | 6.6 |
| 400 | 2.5 | 3.4 | 4.1 | 4.5 | 4.9 | 5.2 | 5.4 | 5.6 | 5.7 | 5.7 |
| 500 | 2.2 | 3.1 | 3.6 | 4.1 | 4.4 | 4.7 | 4.8 | 5.0 | 5.1 | 5.1 |
| 600 | 2.0 | 2.8 | 3.3 | 3.7 | 4.0 | 4.3 | 4.4 | 4.5 | 4.6 | 4.6 |
| 700 | 1.9 | 2.6 | 3.1 | 3.4 | 3.7 | 3.9 | 4.1 | 4.2 | 4.3 | 4.3 |
| 800 | 1.8 | 2.4 | 2.9 | 3.2 | 3.5 | 3.7 | 3.8 | 3.9 | 4.0 | 4.0 |
| 900 | 1.7 | 2.3 | 2.7 | 3.0 | 3.3 | 3.5 | 3.6 | 3.7 | 3.8 | 3.8 |
| 1,000 | 1.6 | 2.2 | 2.6 | 2.9 | 3.1 | 3.3 | 3.4 | 3.5 | 3.6 | 3.6 |
| 1,200 | 1.4 | 2.0 | 2.3 | 2.6 | 2.8 | 3.0 | 3.1 | 3.2 | 3.3 | 3.3 |
| 1,400 | 1.3 | 1.8 | 2.2 | 2.4 | 2.6 | 2.8 | 2.9 | 3.0 | 3.0 | 3.0 |
| 1,600 | 1.2 | 1.7 | 2.0 | 2.3 | 2.5 | 2.6 | 2.7 | 2.8 | 2.8 | 2.8 |
| 1,800 | 1.2 | 1.6 | 1.9 | 2.1 | 2.3 | 2.5 | 2.6 | 2.6 | 2.7 | 2.7 |
| 2,000 | 1.1 | 1.5 | 1.8 | 2.0 | 2.2 | 2.3 | 2.4 | 2.5 | 2.5 | 2.5 |
| 2,500 | 1.0 | 1.4 | 1.6 | 1.8 | 2.0 | 2.1 | 2.2 | 2.2 | 2.3 | 2.3 |
| 3,000 | 0.9 | 1.2 | 1.5 | 1.7 | 1.8 | 1.9 | 2.0 | 2.0 | 2.1 | 2.1 |
| 3,500 | 0.8 | 1.2 | 1.4 | 1.5 | 1.7 | 1.8 | 1.8 | 1.9 | 1.9 | 1.9 |
| 4,000 | 0.8 | 1.1 | 1.3 | 1.4 | 1.6 | 1.6 | 1.7 | 1.8 | 1.8 | 1.8 |
| 5,000 | 0.7 | 1.0 | 1.1 | 1.3 | 1.4 | 1.5 | 1.5 | 1.6 | 1.6 | 1.6 |
| 6,000 | 0.6 | 0.9 | 1.0 | 1.2 | 1.3 | 1.3 | 1.4 | 1.4 | 1.5 | 1.5 |
| 7,000 | 0.6 | 0.8 | 1.0 | 1.1 | 1.2 | 1.2 | 1.3 | 1.3 | 1.4 | 1.4 |
| 8,000 | 0.6 | 0.8 | 0.9 | 1.0 | 1.1 | 1.2 | 1.2 | 1.2 | 1.3 | 1.3 |
| 9,000 | 0.5 | 0.7 | 0.9 | 1.0 | 1.0 | 1.1 | 1.1 | 1.2 | 1.2 | 1.2 |
| 10,000 | 0.5 | 0.7 | 0.8 | 0.9 | 1.0 | 1.0 | 1.1 | 1.1 | 1.1 | 1.1 |
| 12,000 | 0.5 | 0.6 | 0.7 | 0.8 | 0.9 | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 |
| 14,000 | 0.4 | 0.6 | 0.7 | 0.8 | 0.8 | 0.9 | 0.9 | 0.9 | 1.0 | 1.0 |
| 16,000 | 0.4 | 0.5 | 0.6 | 0.7 | 0.8 | 0.8 | 0.9 | 0.9 | 0.9 | 0.9 |
| 18,000 | 0.4 | 0.5 | 0.6 | 0.7 | 0.7 | 0.8 | 0.8 | 0.8 | 0.8 | 0.8 |
| 20,000 | 0.4 | 0.5 | 0.6 | 0.6 | 0.7 | 0.7 | 0.8 | 0.8 | 0.8 | 0.8 |
| 25,000 | 0.3 | 0.4 | 0.5 | 0.6 | 0.6 | 0.7 | 0.7 | 0.7 | 0.7 | 0.7 |
| 30,000 | 0.3 | 0.4 | 0.5 | 0.5 | 0.6 | 0.6 | 0.6 | 0.6 | 0.7 | 0.7 |
| 35,000 | 0.3 | 0.4 | 0.4 | 0.5 | 0.5 | 0.6 | 0.6 | 0.6 | 0.6 | 0.6 |
| 40,000 | 0.2 | 0.3 | 0.4 | 0.5 | 0.5 | 0.5 | 0.5 | 0.6 | 0.6 | 0.6 |
| 45,000 | 0.2 | 0.3 | 0.4 | 0.4 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 |
| 50,000 | 0.2 | 0.3 | 0.4 | 0.4 | 0.4 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 |
e.g. an estimate of 55% that is based on a sample of 800 has 95% confidence limits of 55% ± 4.1% points
2013 Design factor = 1.16
Formula used is CI = 1.16 x 1.96 x SQRT((% x (1-%)) / n )
The following tables replicate earlier travel diary tables using an updated methodology to calculate travel distances, more information on the methodological changes can be found in the 'Calculating Distance' section of Appendix A of Transport and Travel in Scotland 2013.