Consider the figure below. What are the cases in the data? Whatvariables are used? Are they categorical or quantitative?

Did the percentage of calories consumed from fast food differ bysex or age? Identify the explanatory variable and the responsevariable if it makes sense to do so.

Mean percentage of calories from fast food among children andadolescents aged 2–19 years, by sex and age: United States,2011–2012.

• A :

  The variables are children aged 2 – 11 and adolescents aged 12 –19 in the United States.

  The cases are sex, age, and the average percentage of caloriesconsumed.

  These are quantitative variables. The question indicates that wethink sex or age might influence the percentage of caloriesconsumed. So we call sex and age the explanatory variables andpercentage of calories consumed the response variable.

• B :

  The variable is the average percentage of calories consumed.

  The case is age.

  This is a quantitative variable. The question indicates that wethink age might influence the percentage of calories consumed. Sowe call age the explanatory variable and percentage of caloriesconsumed the response variable.

• C :

  The variables are sex, age, the average percentage of caloriesconsumed.

  The cases are children aged 2-11 and adolescents aged 12–19years in the United States.

  These are one categorical variable and two quantitativevariables. The question indicates that we think sex or age mightinfluence the percentage of calories consumed. So we call sex andage the response variables and percentage of calories consumed theexplanatory variable.

• D :

  The variables are sex, age, the average percentage of caloriesconsumed.

  The cases are children aged 2-11 and adolescents aged 12–19years in the United States.

  These are one categorical variable and two quantitativevariables. The question indicates that we think sex or age mightinfluence the percentage of calories consumed. So we call sex andage the explanatory variables and percentage of calories consumedthe response variable.

• E :

  The variables are children aged 2-11 and adolescents aged 12–19years in the United States.

  The cases are sex, age, and the average percentage of caloriesconsumed.

  These are categorical variables. The question indicates that wethink sex or age might influence the percentage of caloriesconsumed. So we call sex and age the response variables andpercentage of calories consumed the explanatory variable.