4.1 Explanatory and Response Variables? You have data on a large group of college students. Here are four pairs of variables measured on these students. For each pair, 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) Number of lectures attended in your statistics course and grade on the final exam for the course

(b) Number of hours per week spent exercising and calories burned per week

(c) Hours per week spent online using Facebook and grade point average

(d) Hours per week spent online using Facebook and IQ