Among a clinic's patients having high blood cholesterol levels of at least 240 milliliters per deciliter of blood serum, the previous drug they are on has no changes in their blood cholesterol levels....

Extracted text: Among a clinic's patients having high blood cholesterol levels of at least 240 milliliters per deciliter of blood serum, the previous drug they are on has no changes in their blood cholesterol levels. Volunteers were asked to test a new drug designed to reduce blood cholesterol. A group of 40 volunteers were given the drug for 60 days, and the changes in their blood cholesterol levels were noted. If the average change was a decrease of 6.8 with a sample standard deviation of 12.1, what conclusions can we draw? Use the 5 percent level of significance.