Answer:
The critical z-value for a confidence level of 85% is ±1.439.
Step-by-step explanation:
The critical value of a distribution is the value beyond which the rejection region lies.
For a confidence interval the rejection region lies beyond two values, the positive and the negative critical value.
The confidence level is, 85%.
Compute the critical value of z for 85% confidence level as follows:
[tex]\pm z_{\alpha/2}=\pm z_{0.15/2}=\pm z_{0.075}=\pm1.439[/tex]
*Use a z-table for the value.
Thus, the critical z-value for a confidence level of 85% is ±1.439.
