in a test of the effectiveness of garlic for lowering cholesterol, 42 subjects w
ID: 3339427 • Letter: I
Question
in a test of the effectiveness of garlic for lowering cholesterol, 42 subjects were treated with garlic in a processed tablet form. Cholesterol levels were measured before and after the treatment. The changes in their levels of LDL cholesterol (in mg/dL) have a mean of 3.3 and a standard deviation of 17.7.
a. what is the best point estimate of the population mean net change in LDL cholesterol after the garlic treatment?
The best point estimate is ?? mg/dl (type an intergar or a decimal)
b. Construct a 90% confidence interval estimate of the mean net change in LDL chloesterol after the garlic treatment. What does the confidence interval suggest about the effectiveness of garlic in reducing LDL cholesterol?
What is the confidence interval estimate of the population mean ?
?? mg/dl < < ?? mg/dl (round to TWO decimal places)
c. what does the confidence interval suggest about the effectivness of the treatment?
(a). the confidence interval limits do not contain 0, suggesting that the garlic treatment did affect the ldl cholesterol levels.
(b). the confidence interval limits contain 0, suggesting that the garlic treatment did affect the ldl cholesterol levels.
(c). the confidence interval limits do not contain, 0, suggesting that the garlic treatment did not affect the ldl chloesterol levels.
(d). the confidence interval limits contain 0, suggesting that the garlic treatment did not affect the ldl cholesterol levels
Explanation / Answer
a) best point estimate is 3.3 mg/dl
b) for std error of mean =std deviation/(n)1/2 =17.7/(42)1/2 =2.7312
for 90% Ci and (42-1=41) degree of freeom ; critical value of t =1.6829
hence 90% confidence interval =sample mean -/+ t*std error =-1.30 to 7.90
c)
(d). the confidence interval limits contain 0, suggesting that the garlic treatment did not affect the ldl cholesterol levels
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.