In test of the effectiveness of garlic for loweringcholesterol, 48 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 4.2 and standard deviation of 16.5

Complete parts(a) and(b) below.

a. What is the best point estimate of the population mean net change in LDL cholesterol after the garlictreatment?

The best point estimate is

mg/dL.

(Type an integer or adecimal.)

b. Construct a 99% 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 mu?

mg/dL

(Round to two decimal places asneeded.)