Table 1. Critical (z) values used in the calculation of confidence intervals.
| Confidence level | Critical (z) value to be used in confidence interval calculation |
|---|---|
| 50% | 0.67449 |
| 75% | 1.15035 |
| 90% | 1.64485 |
| 95% | 1.95996 |
| 97% | 2.17009 |
| 99% | 2.57583 |
| 99.9% | 3.29053 |
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