Question

A medical researcher is studying the effects of a drug on blood pressure. Subjects in the study have their blood pressure taken at the beginning of the study. After being on the medication for 4 weeks, their blood pressure is taken again. The change in blood pressure is recorded and used in doing the hypothesis test. Change: Final Blood Pressure - Initial Blood Pressure The researcher wants to know if there is evidence that the drug increases blood pressure. At the end of 4 weeks, 34 subjects in the study had an average change in blood pressure of 2.5 with a standard deviation of 5.1. Find the p -value for the hypothesis test. Your answer should be rounded to 4 decimal places.

Answer 1

We need to test the claim that the diet is effective in reducing weight. Therefore, we are testing the claim that the drug increases blood pressure, After - Before is > 0.

Given: Mean of the differences() = 2.5 and Std Deviation of differences (sd) = 5.1

The degrees of freedom (df) = n - 1 = 34 - 1 = 33

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The Hypothesis:

H0: = 0

H0: > 0

The Test Statistic:

P value: The p value (Right tailed) for t = 2.858, df = 33; p value = 0.0037

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If we use = 0.05 (default), the decision rule is that if p value is < , then Reject H0.

Here we see that the p value (0.0037) is < (0.05), therefore we reject H0.

The Conclusion is that there is sufficient evidence at the 95% significance level to conclude that the drug increases blood pressure.

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