9.1. A study investigates home Internet use, measured as (none, <1 hour a day, > 1 hour a day), for subjects in families living in a rural location and families living in an urban area. Each cluster consists of the people in a particular family. For this study, give an example of a

(a) within-cluster effect and

(b) between-cluster effect. Explain why you would expect the within-cluster correlation to be positive, and in each case, explain how the actual standard errors would compare to those obtained with the same number of independent observations.