Hypothesis-Power of Hypothesis


Could someone advise me if my answer is correct as I found this question somewhere online?

Q: All else being equal, the power of a hypothesis test is most likely to increase as:
A: the likelihood of a Type I error increases.
B: the likelihood of a Type II error decreases.
C: the likelihood of a Type II error increases.

I think the answer is “C”.

The power of a test (not the power of an hypothesis, by the way) is the probability of rejecting a false null hypothesis. Therefore:

Power of the test = 1 − P(failing to reject a false H0) = 1 − P(Type II error).

Therefore, the power of the test will increase when the probability of a Type II error decreases: B.

Thanks millions for the explanation! I guess I will have to re-read the chapter, I am getting so confused and mixed up :frowning:

Have a great day.

You’re quite welcome.

Have a great day yourself!