What does it mean for a confidence interval for the difference of two means to contain zero?
A)You are unable to say there is a difference in the population means.
B)Different samples could give results in either direction; completely above zero, completely below zero, or containing zero.
C)The confidence interval will contain some negative numbers and some positive numbers.
D)All of the above.

Question

Quizplus · Accepted Answer

When a confidence interval for the difference of two means contains zero, it implies that there is a possibility that there is no difference between the population means (A), that different samples could yield intervals that are above, below, or contain zero (B), and that the interval itself will have both negative and positive numbers, indicating uncertainty about the direction of the difference (C). Thus, all the given options are correct interpretations.

What Does It Mean for a Confidence Interval for the Difference