Association. 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 and form.

a) Salespersons’ earning: Distance traveled (miles), sales ($).

b) Academic result: Time spent studying per week (hours), scores achieved.

c) Laptop performance: Life of a laptop battery (years), number of times fully charged.

d) Sales profit: Profit earned ($), expenses on advertisement ($).