4 because if you divide 120/30 you get 4
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:
brainly.com/question/27003351
Answer:
$16.12
Step-by-step explanation:
55% of $10.40 = 0.55 × $10.40 = $5.72
$10.40 + $5.72 = $16.12