Describe how you would look up the critical zvalue for a 72

Describe how you would look up the critical z-value for a 72% on a normal curve table, what is the critical z-value for a 72% confidence interval?

Solution

    Za/2 = Z-table value = 1.08

Method 1:
I will use the below formula NORMINV(1-0.28/2,0,1)
Method 2:
To do this, if X ~ N(?, ?^2), then
   STEP 1:
Z= X- ? / ? ~ N(0,1)
STEP 2:
A table of standardized normal values, can then be used to obtain an answer in terms of the converted problem.
STEP 3:
Find x=Z ?+ ?

STEP 4:
Use below method
http://www.mathsisfun.com/data/standard-normal-distribution-table.html

Eg:
TYPE 1: (Z ? 1.65) = F(1.65) = 0.95