1. Consider the following data sets that could be found in the Exercises folder of the diskette or DataMarket—Time Series Data Library.

For each data set: (a)–(e)

(i) Scan the data into R.

(ii) Plot the data versus time.

(iii) Describe what signal might fit the data. If the data appears periodic, guess what the period might be.

Meteorology:

(a) Daily maximum temperatures in Melbourne, Australia, 1981–1990 [Exercises folder, “Melbmax.txt”].

(b) Monthly Southern Oscillation Index measured as the difference in sea-surface air pressure between Darwin and Tahiti, January 1882–May 1993 [Exercises folder, “oscillations.txt”].

Agriculture:

(c) Monthly milk production: pounds per cow, January 1962–December 1975 [Exercises folder, “milk production.txt”].
Ecology:

(d) Annual number of lynx pelts (Hudson’s Bay Company, Canada), 1857–1911 [Exercises folder, “LYNX.txt”].
Miscellaneous:

(e) Monthly average daily calls to directory assistance, January 1962–December 1976 [Examples folders, “directory assistance.txt”].