Suppose television advertisers want to know if age plays a role in people's response to a rather unconventional ad that may be aired during the next Super Bowl. The ad is shown to a variety of viewers. Keeping in mind that the explanatory variable is not necessarily the first one mentioned, classify each of the following possible approaches as involving one of these relationships:

CC: categorical explanatory variable and categorical response variableCQ: categorical explanatory variable and quantitative response variableQC: quantitative explanatory variable and categorical response variableQQ: quantitative explanatory variable and quantitative response variable

(a) They ask whether or not a viewer likes the ad, and record his or her age.

CC

CQ

QC

QQ

(b) They classify a viewer as being youth, young adult, middle-aged, or senior citizen, and whether or not he or she likes the ad.

CC

CQ

QC

QQ

(c) Viewers' ages are recorded, along with their rating of the ad on a scale of 1 (most unfavorable) to 10 (most favorable).

CC

CQ

QC

QQ

(d) Viewers' ratings of the ad on a scale of 1 to 10 are recorded, along with the viewers' age group as being youth, young adult, middle-aged, or senior citizen.

CC

CQ

QC

QQ