PROBLEMS:
1. A study of young children found that those with more body fat tended to have more "controlling" mothers; the San Francisco Chronicle (november 9, 1994) concluded that "Parents of Fat Kids Should Lighten Up."
    a) Was this an observational study or a randomized controlled experiment?
    b) Did the study find an association between mother's behavior and her child's level of body fat?
    c) If controlling behavior by the mother causes children to eat more, would that explain an association between controlling behavior by the mother and her child's level of body fat?
    d) Suppose there is a gene which causes obesity.  Would that explain the association?
    e) Can you think of another way to explain the association?
    f) Do the data support the Chronicle's advice on child-rearing?
Discuss each briefly.

2. Can people tell the difference between Coke and Pepsi?  Design an experiment to find out.  Explain why your design is a good one.  You should address the issues of a) representativeness, b) bias c) confounding factors.
WARNING: This is a good problem to discuss in class. Be Prepared!

3. A random sample of income tax returns is used to find 1000 people's income.
    a) Would you expect the median income in this sample to be about the same as, more than, or less than, the average of this sample?
    b) Suppose that next year, everyone in this sample gets a $1000 raise.  How would the median change?  How would the average change?  How about the inter-quartile range and the standard deviation?  Explain.
    c) Suppose that next year, everyone in our sample gets a 10% raise.  How would this affect the median, average, SD and inter-quartile range? Explain.

4.   On Wednesday night's McNiel News Hour (PBS), an essayist was trying to make the point that public schools in the Silicon Valley were very poor.  He said "Only 51% of the students score above the national median on reading scores."  Do you find this alarming?  Why?

Also, in Chapter 4 (p. 131) do 4.1,4.2, 4.11.