If p-value < 0.05, what conclusion?

If p-value < 0.05, what conclusion?

• A. Fail to reject null; not enough evidence
• B. Conclude identical rates
• C. Reject null; mortality rates differ between groups
• D. Accept the alternative

Answer: (C)

The main idea is what p-values tell you about evidence against the null hypothesis in a hypothesis test. A p-value below the 0.05 threshold means the observed difference in mortality rates is unlikely to occur if there were no real difference between groups. So you reject the null hypothesis and conclude there is statistically significant evidence that mortality rates differ between the groups. This doesn’t prove the rates are identical or that the alternative is proven true; it simply indicates a difference is supported by the data. Saying you “accept” the alternative isn’t the standard phrasing; you conclude there is evidence of a difference.

The main idea is what p-values tell you about evidence against the null hypothesis in a hypothesis test. A p-value below the 0.05 threshold means the observed difference in mortality rates is unlikely to occur if there were no real difference between groups. So you reject the null hypothesis and conclude there is statistically significant evidence that mortality rates differ between the groups. This doesn’t prove the rates are identical or that the alternative is proven true; it simply indicates a difference is supported by the data. Saying you “accept” the alternative isn’t the standard phrasing; you conclude there is evidence of a difference.