When the 95% confidence interval of the mean of one group does not include 0, it means that the difference between two groups is statistically significant at the .05 level

Question

Quizplus · Accepted Answer

The statement about the 95% confidence interval not including 0 refers to the mean of a single group, not the difference between two groups. Statistical significance of a difference between two groups would be assessed by looking at the confidence interval of the difference between their means, not the mean of one group alone.

When the 95% Confidence Interval of the Mean of One