In a test of the effectiveness of garlic for lowering cholesterol, 47 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 2.9 and a standard deviation of 15.8.

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 ___mg/dL.

(Use an integer or a decimal.)

b. Construct a 90% 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 LDLcholesterol?

What is the confidence interval estimate of the population mean ?

___mg/dL <<___ mg/dL

(Round to two decimal places as needed.)

What does the confidence interval suggest about the effectiveness of the treatment?

A.The confidence interval limits do not containdonotcontain 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 notcontain 0, suggesting that the garlic treatment did not affect the LDL cholesterol levels.

D.The confidence interval limits contain 0, suggesting that the garlic treatment didnot affect the LDL cholesterol levels.