1. Problem 2.1, page 55 from Weisberg. Data sets are ALR056 and ALR057. Omit part 2.1.5.
2. [This problem is adapted from Problem 2.8, pages 62--63 of
Weisberg. Answer the questions here rather than the questions in
High ozone levels represent one measure of air quality. From 1965 through 1977, the number of days each year in the San Francisco Bay area on which the ozone level exceeded federal standards for at least one hour showed a decline of approximately 5% per year. These levels show some large, unexplained fluctuations, however. One possible factor causing these variations might be the weather from the previous year or two years. For example, winter rainfall might influence ozone levels in the following summer. The data in ALR063 are from a study of Sandberg, Basso, and Okin (1978). The variables occur in the following order.
YEAR = Year of ozone measurement RAIN = Average winter precipitation (cm) for preceding two winters SF = Summer quarter maximum hourly average ozone reading (ppm) at San Francisco SJ = Summer quarter maximum hourly average ozone reading (ppm) at San Jose, a city at the southern end of the Bay.
3. This problem should be submitted on a separate piece of paper from the other parts. It will be separated (temporarily) from the rest of your homework set.
For purposes of this exercise, suppose that you were the investigator in the preceding problem. Write a paragraph of no more than 100 words describing your results, for publication in the Science section of the Chicago Tribune.