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A study compared union activity of employees in 10 plants during two different d

ID: 3292562 • Letter: A

Question

A study compared union activity of employees in 10 plants during two different decades. The researchers reported "a significant increase in union activity, t(9)=3.13, p < 0.01. "Explain this result to a person who has never had a course in statistics. Be sure to use sketches of the distributions in your answer.

Which statement below best explains this result?

A. The difference between the two population means is less than 0.01. Since p < 0.01,the chance these results came from the hypothetical distribution of no change is less than a 1%, so the researcher can conclude there was an increase in union activity.

B. The mean change score for the sample is 3.13 standard deviations above the mean change of 0. Since p < 0.01, the chance these results came from the hypothetical distribution of no change is less than a 1%, so the researcher can conclude there was an increase in union activity.

C. The mean change for the sample is 3.13. Since p<0.01, the chance these results came from the hypothetical distribution of no change is less than a 1%, so the researcher can conclude there was an increase in union activity.

Explanation / Answer

option B) is correct

B. The mean change score for the sample is 3.13 standard deviations above the mean change of 0. Since p < 0.01, the chance these results came from the hypothetical distribution of no change is less than a 1%, so the researcher can conclude there was an increase in union activity.