In a test of the effectiveness of garlic lowering cholesterol, 49 subjects were treated with garlic in a processed tablet form. cholesterol levels were monitored before and after the treatement. the changes in their levels of ldl cholesterol in mg/dl have a mean of 3.5 and a sd of 18.1.
A. What is the best point of est of the population mean net change ldl cholesterol after the garlic treatmemnt.
B. Construct a 95% confidence internal est of the mean net change