A researcher collected blood cholesterol levels of men in three different socioeconomic groups labeled I, II, and III to study whether there is a significant difference between the mean blood cholesterol of the three groups. The data are provided below.

I	II	III
403	312	403
311	222	244
269	302	353
336	420	235
259	420	319

1. What test should the researcher use for the study?

2. Write down the null hypothesis.

3. What's the degrees of freedom for the between group variation?

4. What's the degrees of freedom for the within group variation?

5. What test should be used to compare the mean cholesterol levels between the three groups?

6. What are the assumptions behind the analysis?