Answer :
The correct answer which refers to the z-statistic for this data is b)0.90.
What is a Hypothesis Test?
The hypothesis Test refers to the statistical approach where the test is applied to an assumption regarding a population parameter.
It is given that µ = 115 and Sigma = 30.
sample size is 25 with a mean of 120.4
The formular for z-statistic is
z = (x – u) / (σ / sqrt n)
Therefore, we input the values and we get
z = (120.4 – 115) / (30 / sqrt 25)
We calculate further and we get
z = 0.90
Therefore, the correct answer is option b.
Learn more about the hypothesis test here:
brainly.com/question/4599596