2. 4.27. Explanatory and response variables. In each of the following situations, is it more reasonable to simply explore the relationship between the two variables or to view one of the variables as an explanatory variable and the other as a response variable? In the latter case, which is the explanatory variable and which is the response variable? (a) The weight of a child and the age of the child from birth to 10 years. Explanatory variable: weight; response variable: age (b) High school English grades and high school math grades. Relationship between two variables (c) The rental price of apartments and the number of bedrooms in the apartment. Explanatory variable: number of bedrooms in the apartment: Response variable. rental price of apartment