If p-value = 0.03 and α = 0.05, should you reject H0?

• A. Yes
• B. No
• C. Not enough information
• D. The p-value is greater than α

Answer: (A)

In hypothesis testing, you compare the p-value to your chosen significance level to decide whether to reject H0. The p-value is the probability, under the null hypothesis, of obtaining results as extreme as the observed data. The significance level α sets how willing you are to make a Type I error (rejecting a true H0).

Since the p-value is 0.03 and α is 0.05, 0.03 ≤ 0.05, so the result is statistically significant at the 5% level. You reject H0 and conclude there is evidence against it in favor of the alternative.

The other options don’t fit: not enough information isn’t needed because both p-value and α are given, and saying the p-value is greater than α is false because 0.03 is not greater than 0.05.