Reference Tables
Useful academic, statistical and scientific reference tables.
Quick reference tables for common educational and scientific work.
Common two-sided normal critical values
| Confidence level | Z critical value |
|---|---|
| 80% | 1.282 |
| 90% | 1.645 |
| 95% | 1.960 |
| 98% | 2.326 |
| 99% | 2.576 |
Selected SI prefixes
| Prefix | Symbol | Factor |
|---|---|---|
| nano | n | 10−9 |
| micro | µ | 10−6 |
| milli | m | 10−3 |
| kilo | k | 103 |
| mega | M | 106 |
Common fraction equivalents
| Fraction | Decimal | Percent |
|---|---|---|
| 1/2 | 0.5 | 50% |
| 1/3 | 0.333… | 33.33…% |
| 1/4 | 0.25 | 25% |
| 1/5 | 0.2 | 20% |
| 3/4 | 0.75 | 75% |