Question: The Environmental Protection Agency (EPA) is charged with monitoring the environment. One aspect of this is keeping track of "acid rain," a broad term describing the fall of acid from the atmosphere. Acidity is measured on the pH scale, where pure water has a pH of 7.0. Normal rain is slightly acidic because carbon dioxide dissolves into it, and thus has a pH of about 5.5. (A lower pH indicates greater acidity.) Suppose the EPA wishes to determine whether a particular area is subjected to acid rain. Let μ denote the true average for pH in this area.

*What is the appropriate null hypothesis and the appropriate alternative hypothesis?

*Distinguish between a Type I and a Type II error in this context.