Your friend Zoe is very earnest about the benefits of her special diet. She believes that having kale for breakfast every day will lower your cholesterol.4a. What's the best method for testing Zoe's claim: a survey, an observational study, or an experiment? Give at least one reason to support your answer. (4 points)4b. Describe how you would set up a test to determine how much truth there is to Zoe's claims. In particular, what steps would you take to make sure the results were unbiased and valid?

- The best method to test Zoe's claim is an observational study, as with this method it is possible to observe if the claim presents some truth to it. Observational studies are often used in testing claims like Zoe's as they allowed to have a great access to the variable that are behind a claim of that type, and so they are also more accessible.

- The set up I would use is an observational study of a great number of people, over a long period of time, that have to have kale for breakfast every day, with a measurement of their cholesterol over the time. the great number and the long period of study assured that the variable subject of study is statistically represented in an optimal way.