Would you expect a positive, negative, or nearly zero correlation for each of the following? Give reasons for your answers.
(a) The physical fitness of a dog and the physical fitness of the owner.
(b) For each person, the number of songs downloaded from the Internet last month and the number of hours listening to MP3 format music.
(c) For a student, the number of friends listed on their personal Internet sites and the number of hours they are active on the Internet.