Study Design 2: One hundred people who live in Miami volunteered to participate in a statistical study. The volunteers were divided into two experimental groups based on gender, with women in group 1 and men in group 2. Those in group 1 were asked to eat 6 ounces of sweet potatoes daily for 3 months. Those in group 2 were asked not to eat any sweet potatoes for 3 months. At the end of the 3 months, a skin specialist rated skin health on a scale of 1 to 10 for each of the volunteers. It was concluded that skin health was significantly better on average for group 1 than for group 2.

1. Is the study described an observational study or an experiment? Explain your answer.
2. Did the study use random selection from some population? If so, what did the study researchers do to randomly select students?
3. Did the study use random assignment to experimental groups? If so, explain what the study did to randomly assign students?
4. Is the conclusion "eating sweet potatoes leads to healthier skin" reasonable given the study description? Explain your answer.
5. Is it reasonable to generalize conclusions from this study to some larger population? If so, what population?