Suppose you were to collect data for each pair of variables. You want to make a scatterplot. Which variable would you use as the explanatory variable and which as the response variable? Why? What would you expect to see in the scatterplot? Discuss the likely direction, form, and strength.
a) T-shirts at a store: price each, number sold
b) Scuba diving: depth, water pressure
c) Scuba diving: depth, visibility
d) All elementary-school students: weight, score on a reading test.