Question

Find the critical value z Subscript alpha divided by 2zα/2 that corresponds to the given confidence level. 94%

Answer 1

The critical value is z=1.88.

We find this by first converting the percent confidence we want to a decimal:  94% = 94/100 = 0.94

We subtract that from 1 to find the alpha level:
1-0.94 = 0.06

Divide this by 2 (to find the area in each tail):
0.06/2 = 0.03

Subtract this from 1 again (because we want the area in the middle, not in each tail):
1 - 0.03 = 0.97

Using a z-table (http://www.z-table.com) we see that the closest to this in the table is at z = 1.88.