z-score | p-value | Confidence level |
z-score < −1.65 or z-score > +1.65 | <0.10 | 90% |
z-score < −1.96 or z-score > +1.96 | <0.05 | 95% |
z-score < −2.58 or z-score > +2.58 | <0.01 | 99% |