A researcher has developed a new drug designed to reduce blood pressure. In an experiment, 21 subjects were assigned randomly to the treatment group, and received the new experimental drug. The other 23 subjects were assigned to the control group, and received a standard, well-known treatment. After a suitable period of time, the reduction in blood pressure for each subject was recorded. A summary of these data is:
1.) A 95% confidence interval for the difference in reduction of blood pressure between these two drugs is (use Option 2, the conservative method for degrees of freedom)?
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A.
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0.17 to 9.75 points.
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B.
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0.45 to 9.46 points.
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C.
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1.26 to 8.66 points.
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D.
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1.35 to 8.57 points.
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2.) The computed two-sample t statistic is?
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A.
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1.84.
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B.
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2.16.
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C.
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2.31.
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D.
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4.70.
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3.) The P-value for the test described in Question 5 (again, using Option 2 for degrees of freedom) is?
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A.
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larger than 0.05.
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B.
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between 0.025 and 0.05.
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C.
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between 0.04 and 0.05.
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D.
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between 0.02 and 0.025.
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4.) Which of the following would lead us to believe that the t procedures were notsafe to use here?
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A.
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The two population distributions being studied are slightly non-Normal.
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B.
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The sample medians and means for the two groups were slightly different.
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C.
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The two population distributions are heavily skewed and far from Normal.
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D.
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Some subjects did not follow protocol, and these could be outliers in the data.
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