2.6 Explanatory or response? For each of the following scenarios, classify each of the pair of variables as explanatory or response or neither. Give reasons for your answers.

1. (a) Whether or not a person likes to sing and whether or not a person likes to dance.

2. (b) The number of pages in a textbook and the cost of a new copy of the textbook.

3. (c) The number of alcoholic drinks consumed and the blood alcohol content.

4. (d) In a study of adolescents, the dose of vitamin D given each day for a year (50, 100, or 200 international units) and the change in total bone mineral content from the beginning of the study to the end of the study.