Rey examines the difference in the amount of carbon dioxide in the two types of mineral water. He performs a two-group t-test to compare the average carbon dioxide levels in the two groups. His...

Rey examines the difference in the amount of carbon dioxide in the two types of mineral water. He performs a two-group t-test to compare the average carbon dioxide levels in the two groups. His hypotheses are H0: μ1 −μ2 = 0 and H1: μ1 −μ2 ̸ = 0. Rey also calculated a confidence interval for the difference between the means of the two groups (and used the same α as in the hypothesis test). Rey rejected the null hypothesis. Which of the following applies to the safety margin calculated by Rey?

1. It contains the value zero.


2. It contains 95% of the values that can occur when the experiment is performed. 3. It does not contain the value zero.


3. It contains both values greater than zero and values less than zero.


4. I do not know.