Question 1011625
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 in their levels of LDL cholesterol​ (in mg/dL) have a mean of 3.3 and a standard deviation of 15.2. 
Added::
Ho: u  = 0
Ha: u #  0 (claim that the levels changed) 

Complete parts​ (a) and​ (b) below. 

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 3.3 ​mg/dL.
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B.Construct a 99​% confidence interval estimate of the mean net change in LDL cholesterol after the garlic treatment. 
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What does the confidence interval suggest about the effectiveness of garlic in reducing LDL​ cholesterol?
sample mean = 3.3 ; margin of error = 2.5758*15.2/sqrt(45) = 5.84
99%CI:: 3.3-5.84 < u < 3.3+5.84
99%CI:: -2.54 < u < 9.14
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What is the confidence interval estimate of the population mean mu&#956;&#8203;? 
___ &#8203;mg/< than &#8203;(Round to two decimal places as&#8203; needed.) 

What does the confidence interval suggest about the effectiveness of the&#8203; treatment?

Ans: 
B.The confidence interval limits contain &#8203;0, suggesting that the garlic treatment did not affect the LDL cholesterol levels.
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Cheers,
Stan H.
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