Question

A paired experiment in the article “Airborne Hexavalent Chromium in Southwestern Ontario” has 33 data pairs that yields the following information on the difference (in nanograms/m 3 ) between indoor and outdoor pollutant levels: mean difference d= -0.424, s = .387 (standard deviation of the differences). Does the appropriate confidence interval (CI) for the mean difference support the hypothesis that there IS a difference in indoor and outdoor pollution levels, at the 95% confidence level?   

Group of answer choices

No, because the CI of (-.561,-.287) does not contain 0.

There is insufficient data provided to make any such statement.

Yes, because the CI of (-.561,-.287) does not contain 0.

No, because a CI cannot involve negative numbers.

No, because the CI of (-1.212,+.364) contains 0.

Answer 1