How do you determine the cricitcal regions when using a normal distribution for a hypothesis test?

Question

How do you determine the cricitcal regions when using a normal distribution for a hypothesis test?

Answer 1

"critical region" (z critical value):

the value that captures central z curve area of "confidence level"

Example: confidence level of 99%, z critical value captures a central z curve area of 0.99.  "Look-up" entries for cumulative area (0.9950) are 0.9949  and 0.9951.  Thus 2.575 (or 2.58, to be conservative) should be utilized in a hypothesis for area "to the right" of this z critical value.