A doctor is examining differences between two treatments. He calculated a 95% confidence interval on the mean difference between the two groups. The interval ranged from -1.2 to 3.48. What does this suggest?
A) The mean difference is not significant at the .05 level
B) The mean difference has a small effect size
C) The mean difference is significant at the .05 level, but not at the .01 level.
D) The mean difference is not significant at the .05 level, but could still be significant at the .01 level.

Question

Quizplus · Accepted Answer

Since the 95% confidence interval includes 0 (ranging from -1.2 to 3.48), it suggests that there is no significant difference between the two treatments at the .05 level, as we cannot be 95% confident that the true mean difference is not zero.

A Doctor Is Examining Differences Between Two Treatments