The z value for a 97.8 confidence interval is
Answers
The find the Z score, go to a Z lookup table which is found in a textbook or on an internet source. z table is created to give the possibility in a one-tailed analysis. A confidence interval is a two-tailed examination, in order to prepare the z score for 97.8%, look up the probability of 98.9%.
The value of 98.9% is
0.978 + 1 / 2
0.989 or 98.9%.
This implies the z score is 2.29.
Answer:
The value of z is 2.29
Explanation:
To find the z value, you need to look at the Z look up table and this table is provided in the text book or you can find this table on the internet. In z table we can take the probability in one tailed enquiry and confidence level is two tailed. So when you are looking for the z value for 97.8%, you need to look at the probability of 98.9%. So the value of 98.9% = (0.978+1)/2 = 0.989 and this value will give z score 2.29.