Study Design 3: One hundred people volunteered to participate in a statistical study. For each volunteer, a coin was tossed in order to place them into a group. If the coin landed head up, the volunteer was assigned to group 1. If the coin landed tail up, the volunteer was assigned to group 2. Those in group 1 were asked to eat six ounces of sweet potatoes daily for three months. Those in group 2 were asked not to eat any sweet potatoes for three months. At the end of the three 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 those in group 1 than for those in group 2. A. Is the study described an observational study or an experiment? Explain your answer.
B. Did the study use random selection from some population? If so, what did the study researchers do to randomly select students?
C. Did the study use random assignment to experimental groups? If so, explain what the study did to randomly assign students?
D. is the conclusion "eating sweet potatoes leads to healthier skin" reasonable given the study description? Explain your answer.
E. ls it reasonable to generalize conclusions from this study to some larger population? If so, what population?