Final answer:
The value of z_alpha can be found using a z-table or a calculator. Based on the given information, z0.05 is approximately 1.645.
Step-by-step explanation:
The value of z_alpha can be found using a z-table or a calculator. Since the question provides information about z-values for different areas, we can use these values to find the z-value for alpha = 0.12. According to the given information, the area to the left of z0.05 is 0.95, and the area to the right of z0.05 is 0.05. Since alpha = 0.12 is closer to 0.05 than 0.95, we can use the value of z0.05 as an approximation for z_alpha. Based on the information provided, z0.05 is approximately 1.645.