The data provided (in a separate Excel sheet) are daily stock prices from January 1988 through December 1988, for five aerospace companies, A-E. Given this information, the first step toward answering the questions posed is to reformulate the question in terms of these data. For example, two stocks may be considered similar if they maintain approximately the same level, vary to a similar degree, or tend to move up and down in related ways over some relevant time period. The analysis will use some graphical techniques to examine these aspects of the data.

Month A B C D E Jan $17.22 $50.50 $18.75 $43.00 $60.88 Feb $17.89 $51.38 $19.63 $44.00 $62.00 Mar $18.44 $50.88 $19.88 $43.88 $61.88 Apr $18.67 $51.50 $20.00 $44.00 $62.63 May $17.44 $49.00 $20.00 $41.38 $59.75 Jun $18.11 $49.00 $19.50 $41.88 $59.63 Jul $18.56 $49.38 $19.13 $42.50 $60.75 Aug $18.67 $50.13 $19.25 $43.00 $61.75 Sep $18.56 $49.75 $19.00 $43.25 $61.75 Oct $19.06 $50.50 $19.13 $43.88 $61.88 Nov $19.00 $50.25 $19.63 $44.00 $62.13 Dec $19.06 $49.75 $20.00 $44.38 $61.25