The New York Times reported on a study of gadgets and appliances in American homes. For each of the following results, tell which of the five variable situations is involved, choosing from the following: C: single categorical variable
Q: single quantitative variable
C → Q: categorical explanatory variable and quantitative response variable
C → C: categorical explanatory variable and categorical response variable
Q → Q: quantitative explanatory variable and quantitative response variable Q:
a. For each of the 17 appliances studied, the Times reported the percentage of American homes in 2001 that had the appliance. For example, microwave ovens were in 96% of the homes and answering machines were in 78% of the homes. (1) C (2) Q (3) C → Q (4) C → C (5) Q → Q
b. The study made a comparison of percentage owning each appliance in 2001 to the percentage owning the appliance in 1987. For example, microwave ovens were in 66% of the homes in 1987 as opposed to 96% in 2001. Answering machines were in 10% of the homes in 1987 as opposed to 78% in 2001. (1) C (2) Q (3) C → Q (4) C → C (5) Q → Q
c. The study reported 2.5 television sets owned per household in 2001. (1) C (2) Q (3) C → Q (4) C → C (5) Q → Q