Answer:
The critical z value used to test a null hypothesis is ±1.75.
Step-by-step explanation:
We are given that the data has a normal distribution and the number of observations is greater than fifty.
Also, the hypothesis given to us is;
<u>Null Hypothesis</u>, :
= 3.24
<u>Alternate Hypothesis</u>, :
3.24
This means that our test is two-tailed because in the alternate hypothesis we are concerned with mean value is less than or greater than 3.24.
Also, level of significance (α) = 0.08
Now, for two-tailed test level of significance becomes = = 0.04
So, in the z-table the critical value of x at 4% significance level is given as 1.75.
Since, this is two-tailed test so the critical z value used to test a null hypothesis would be ±1.75.