Statistical Standard Scores and Standard Normal Distributions — The “Z-Table”
Part of the Statistics Workbook For Dummies Cheat Sheet
Statistics are handy when it comes to making predictions, but to make accurate predictions, you need to know how reliable your results are. The following Z- table shows standard scores and percentiles in a standard distribution:
| Standard Score | Percentile | Standard Score | Percentile | Standard Score | Percentile |
|---|---|---|---|---|---|
| –3.4 | 0.03% | –1.1 | 13.57% | +1.2 | 88.49% |
| –3.3 | 0.05% | –1.0 | 15.87% | +1.3 | 90.32% |
| –3.2 | 0.07% | –0.9 | 18.41% | +1.4 | 91.92% |
| –3.1 | 0.10% | –0.8 | 21.19% | +1.5 | 93.32% |
| –3.0 | 0.13% | –0.7 | 24.20% | +1.6 | 94.52% |
| –2.9 | 0.19% | –0.6 | 27.42% | +1.7 | 95.54% |
| –2.8 | 0.26% | –0.5 | 30.85% | +1.8 | 96.41% |
| –2.7 | 0.35% | –0.4 | 34.46% | +1.9 | 97.13% |
| –2.6 | 0.47% | –0.3 | 38.21% | +2.0 | 97.73% |
| –2.5 | 0.62% | –0.2 | 42.07% | +2.1 | 98.21% |
| –2.4 | 0.82% | –0.1 | 46.02% | +2.2 | 98.61% |
| –2.3 | 1.07% | 0.0 | 50.00% | +2.3 | 98.93% |
| –2.2 | 1.39% | +0.1 | 53.98% | +2.4 | 99.18% |
| –2.1 | 1.79% | +0.2 | 57.93% | +2.5 | 99.38% |
| –2.0 | 2.27% | +0.3 | 61.79% | +2.6 | 99.53% |
| –1.9 | 2.87% | +0.4 | 65.54% | +2.7 | 99.65% |
| –1.8 | 3.59% | +0.5 | 69.15% | +2.8 | 99.74% |
| –1.7 | 4.46% | +0.6 | 72.58% | +2.9 | 99.81% |
| –1.6 | 5.48% | +0.7 | 75.80% | +3.0 | 99.87% |
| –1.5 | 6.68% | +0.8 | 78.81% | +3.1 | 99.90% |
| –1.4 | 8.08% | +0.9 | 81.59% | +3.2 | 99.93% |
| –1.3 | 9.68% | +1.0 | 84.13% | +3.3 | 99.95% |
| –1.2 | 11.51% | +1.1 | 86.43% | +3.4 | 99.97% |
