In Testing the Difference Between Two Population Means, Using Two $\bar { x } _ { 1 } - \bar { x } _ { 2 }$

question 18

Multiple Choice

In testing the difference between two population means, using two independent samples, the sampling distribution of the sample mean difference $\bar { x } _ { 1 } - \bar { x } _ { 2 }$ is normal if the:

• A) sample sizes are both greater than 30.
• B) populations are normal.
• C) populations are non-normal and the sample sizes are large.
• D) All of these choices are correct.

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The total amount of money spent on health care services by individuals, businesses, and governments.

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A nation with a significant level of development and standard of living, characterized by a strong industrial base.

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The total amount of money spent on healthcare services and products in the United States, including both public and private expenditures.

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