The value of the z statistic for the considered data is given by: Option A: -3.87 approximately.
<h3>How to find the z score (z statistic) for the sample mean?</h3>If we're given that:
- Sample mean =
- Sample size = n
- Population mean =
- Sample standard deviation = s
Then, we get:
If the sample standard deviation is not given, then we can estimate it(in some cases) by:
where population standard deviation
For this case, we're specified that:
- Sample mean =
= 2.3
- Sample size = n = 15
- Population mean =
= 2.7
- Population standard deviation =
= 0.4
Thus, the value of the z-statistic is evaluated as:
Thus, the value of the z statistic for the considered data is given by: Option A: -3.87 approximately.
Learn more about z statistic here: