SOLUTION: 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 a

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Question 1036783: 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 3.4 and a standard deviation of 18.3.
Construct a 95​% 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?
What is the confidence interval estimate of the population mean μ​?
Thank You for your help.
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
This is a paired t-test
Ho:mean =0
Ha:mean ne0.
alpha=0.05
test stat is t, df=44 critical value abs(t)>2.01
t is mean over SE
calculation: SE is 18.3/sqrt (45)=2.73; mean/SE=1.25
Fail to reject Ho
CI is mean +/- t*SE=3.4 +/-2.01*2.73 and the product is 5.49.
The interval is (-2.09,8.89). The interval contains 0, so 0, or no change, is a plausible value, and there is no convincing evidence that garlic affects LDL cholesterol levels.