In a test of the effectiveness of garlic for lowering​ cholesterol, 5050 subjects were

Question

In a test of the effectiveness of garlic for lowering cholesterol, 5050 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 3.83.8 and a standard deviation of 18.618.6. 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
3.83.8 mg/dL.
(Type an integer or a decimal.)
b. Construct a 9090% 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 muμ?

 

mg/dLless than<muμless than<    mg/dL
(Round to two decimal places as needed.)

Answer 1

 

error = 1.65* 18.6186/sqrt(50) = 4.344

 

   (3.838 - 4.344, 3.838 + 4.344) = ( -0.506, 8.182)