Statistical Error Limits
Normal Universe
95 Percent Confidence
| Response Level % | |||||||||||
| Sample | 50% | 55% | 60% | 65% | 70% | 75% | 80% | 85% | 90% | 95% | 99% |
| 25 | 19.6% | 19.5% | 19.2% | 18.7% | 18.0% | 17.0% | 15.7% | 14.0% | 11.8% | 8.5% | 3.9% |
| 50 | 13.9% | 13.8% | 13.6% | 13.2% | 12.7% | 12.0% | 11.1% | 9.9% | 8.3% | 6.0% | 2.8% |
| 75 | 11.3% | 11.3% | 11.1% | 10.8% | 10.4% | 9.8% | 9.1% | 8.1% | 6.8% | 4.9% | 2.3% |
| 100 | 9.8% | 9.8% | 9.6% | 9.3% | 9.0% | 8.5% | 7.8% | 7.0% | 5.9% | 4.3% | 2.0% |
| 150 | 8.0% | 8.0% | 7.8% | 7.6% | 7.3% | 6.9% | 6.4% | 5.7% | 4.8% | 3.5% | 1.6% |
| 200 | 6.9% | 6.9% | 6.8% | 6.6% | 6.4% | 6.0% | 5.5% | 4.9% | 4.2% | 3.0% | 1.4% |
| 250 | 6.2% | 6.2% | 6.1% | 5.9% | 5.7% | 5.4% | 5.0% | 4.4% | 3.7% | 2.7% | 1.2% |
| 300 | 5.7% | 5.6% | 5.5% | 5.4% | 5.2% | 4.9% | 4.5% | 4.0% | 3.4% | 2.5% | 1.1% |
| 400 | 4.9% | 4.9% | 4.8% | 4.7% | 4.5% | 4.2% | 3.9% | 3.5% | 2.9% | 2.1% | 1.0% |
| 500 | 4.4% | 4.4% | 4.3% | 4.2% | 4.0% | 3.8% | 3.5% | 3.1% | 2.6% | 1.9% | 0.9% |
| 600 | 4.0% | 4.0% | 3.9% | 3.8% | 3.7% | 3.5% | 3.2% | 2.9% | 2.4% | 1.7% | 0.8% |
| 800 | 3.5% | 3.4% | 3.4% | 3.3% | 3.2% | 3.0% | 2.8% | 2.5% | 2.1% | 1.5% | 0.7% |
| 1000 | 3.1% | 3.1% | 3.0% | 3.0% | 2.8% | 2.7% | 2.5% | 2.2% | 1.9% | 1.4% | 0.6% |
| 1200 | 2.8% | 2.8% | 2.8% | 2.7% | 2.6% | 2.5% | 2.3% | 2.0% | 1.7% | 1.2% | 0.6% |
| 1500 | 2.5% | 2.5% | 2.5% | 2.4% | 2.3% | 2.2% | 2.0% | 1.8% | 1.5% | 1.1% | 0.5% |
| 2000 | 2.2% | 2.2% | 2.1% | 2.1% | 2.0% | 1.9% | 1.8% | 1.6% | 1.3% | 1.0% | 0.4% |
| 2500 | 2.0% | 2.0% | 1.9% | 1.9% | 1.8% | 1.7% | 1.6% | 1.4% | 1.2% | 0.9% | 0.4% |
| 5000 | 1.4% | 1.4% | 1.4% | 1.3% | 1.3% | 1.2% | 1.1% | 1.0% | 0.8% | 0.6% | 0.3% |
| 7500 | 1.1% | 1.1% | 1.1% | 1.1% | 1.0% | 1.0% | 0.9% | 0.8% | 0.7% | 0.5% | 0.2% |
| 10000 | 1.0% | 1.0% | 1.0% | 0.9% | 0.9% | 0.8% | 0.8% | 0.7% | 0.6% | 0.4% | 0.2% |
z = 1.96
