Question 823404
in a test of effectiveness of garlic for lowering cholesterol, 50 subjects were treated with garlic in a processed tablet form. Cholesterol levels were measured before and after the treatment. 
The changes in the levels of LDL cholesterol (in mg/dL) have a mean of 4.4 and a standard deviation of 19.4. The best point estimate is 4.4. 
1.) what is 95% confidence interval estimate of the population mean?
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x-bar = 4.4
ME = 1.96*[19.4/sqrt(50)] = 5.27
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4.40-5.27 mg/dL <  mean < 4.40+5.27 (mg/dL)
-0.87 < u < 9.27
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Ho: no difference
Ha: is a difference
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What does the confidence interval suggest about the effectiveness of the treatment: 
A: The confidence interval limits contain 0., suggesting that the garlic treatment did not affect the LDL cholesterol levels. 
B. The confidence interval limits do not contain 0,suggesting that the garlic treatment did not affect the LDL cholesterol levels. 
C. The confidence interval limits do not contain 0,suggesting that the garlic treatment did affect the LDL cholesterol levels. 
D. The confidence interval limits contain 0., suggesting that the garlic treatment did affect the LDL cholesterol levels.
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Ans: Since 0 is in the CI, we fail to reject Ho.
Ans: A
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Cheers,
Stan H.