Answer
P=0.2186, z=±1.96.
Work Step by Step
The P is the probability of the z-score being more than 1.23 or less than -1.23 is the sum of the probability of the z-score being less than -1.23 plus 1 minus the probability of the z-score being less than 1.23, hence:P=0.1093+1-0.8907=0.2186. The critical value is the z-score belonging to 0.025 to the left or right, hence z=±1.96.
