We are about to test a hypothesis using data from a well-designed study. Which is true?
I. A small P-value would be strong evidence against the null hypothesis.
II. We can set a higher standard of proof by choosing α = 10% instead of 5%.
III. If we reduce the alpha level, we reduce the power of the test.
A) none of these
B) I and III only
C) I only
D) III only
E) II only

Question

Quizplus · Accepted Answer

A small P-value indicates strong evidence against the null hypothesis (I is true). Reducing the alpha level (e.g., from 5% to 1%) decreases the probability of a Type I error but also reduces the power of the test (III is true).

We Are About to Test a Hypothesis Using Data from a Well-Designed