Question

In a test of the effectiveness of garlic for lowering cholesterol 50 subjects were treated to with garlic in the process tablet form cholesterol levels were measured Before & After the treatment the changes Before & After and their levels of LDL cholesterol in MG/DL have a mean of 5.4 and a standard deviation of 18.3 construct a 99% confidence interval estimate of the mean net change in LDL cholesterol after the girl it treatment what does this confidence interval suggest about the effectiveness of garlic in reduced the LDL cholesterol?

what is the confidence interval estimate of the population mean?
____ mg/dL <   <______ mg/dL

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 contain 0, suggesting that the garlic treatment did not affect the LDL cholesterol levels.
c) the confidence interval limits contain 0, suggesting that the garlic treatment did affect LDL cholesterol levels.
d) the confidence interval limits do not contain 0, suggesting that the garlic treatment did affect the ldl cholesterol levels.

Answer 1

Solution:

The 99% confidence interval estimate of the mean net change in LDL cholesterol is:

Where:

is the critical value at 0.01 significance level for df = 49

Therefore, we have:

what does the confidence interval suggest about the effectiveness of the treatment?
Answer: b) the confidence interval limits contain 0, suggesting that the garlic treatment did not affect the LDL cholesterol levels.