Question

In a test of the effectiveness of garlic for lowering​ cholesterol, 45 subjects were treated with garlic in a processed tablet form. Cholesterol levels were measured before and after the treatment. The changes ​(beforeminus​after) in their levels of LDL cholesterol​ (in mg/dL) have a mean of 2.9 and a standard deviation of 17.3. Construct a 99​% confidence interval estimate of the mean net change in LDL cholesterol after the garlic treatment. What does the confidence interval suggest about the effectiveness of garlic in reducing LDL​ cholesterol? Click here to view a t distribution table. LOADING... Click here to view page 1 of the standard normal distribution table. LOADING... Click here to view page 2 of the standard normal distribution table. LOADING... What is the confidence interval estimate of the population mean mu​? nothing ​mg/dLless thanmuless than nothing ​mg/dL ​(Round to two decimal places as​ needed.) What does the confidence interval suggest about the effectiveness of the​ treatment? A. The confidence interval limits do not 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 affect the LDL cholesterol levels. C. The confidence interval limits contain ​0, suggesting that the garlic treatment did not affect the LDL cholesterol levels. D. The confidence interval limits contain ​0, suggesting that the garlic treatment did affect the LDL cholesterol levels.

Answer 1

The statistical software output for this problem is:

Hence,

99% confidence interval:

-4.04 < < 9.84

The confidence interval limits contain ​0, suggesting that the garlic treatment did not affect the LDL cholesterol levels. Option C is correct.