Question: A researcher for a cereal company wanted to demonstrate the health benefits of eating oatmeal. A sample of 9 volunteers was obtained and each participant ate a fixed diet without any oatmeal for 30 days. At the end of the 30-day period, cholesterol was measured for each individual. Then the participants began a second 30-day period in which they repeated exactly the same diet except that they added 2 cups of oatmeal each day. After the second 30-day period, cholesterol levels were measured again. The scores for the 9 participants are as follows: 0, -2, -11, -15, -12, +3, -9, -9, -8 (a negative scores indicates a decrease in cholesterol level).

Are the data sufficient to demonstrate a significant change in cholesterol level after 30 days with an oatmeal diet? Use a two-tailed test with α =.05.