Study Design 1: Two hundred students were selected at random from those enrolled at a large college in California. Each student in the sample was asked whether he or she ate sweet potatoes more than once in a typical week. A skin specialist rated skin health for each student on a scale of 1 to 10. It was concluded that skin health was significantly better on average for the group that reported eating sweet potatoes more than once a week than it was for the group that did not.

1.) Is the study described an observational study or an experiment? Explain your answer.

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2.)Did the study use a random selection from some population? If so, what did the study researchers do to randomly select students?

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3.)Did the study use random assignment to experimental groups? If so, explain what the study did to randomly assign students?

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4.)Is the conclusion "eating sweet potatoes leads to healthier skin" reasonable given the study description? Explain your answer.

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5.)Is it reasonable to generalize conclusions from this study to some larger population? If so, what population?