do we have to memorize the critical points for 1, 5, and 10 significance level or we can see that in a z- table?
I have the same question. Has anyone met these problems during level 1 exam?
You should know (for a 2-tailed test):
- 68% is 1_σ_
- 90% is 1.645_σ_
- 95% is 1.96_σ_
- 99% is 2.58_σ_
If they want any other percentage, they’ll give you an excerpt from a standard normal distribution table.