To solve this problem, we have to make use of the standard
probability distribution tables for z test.
Since we are asked to find for the 72 percent level
confidence, then this means we are to look for the value of z which gives
(100-72)/2 = 14% on both sides of the tail.
So at 14% tail on one side, the z value is approximately:
1.08
Answer:
± 1.08
