1.15 GPA and study hours: A survey was conducted on 193 Duke University undergraduates who took an introductory statistics course in 2012. Among many other questions, this survey asked them about their GPA, which can range between 0 and 4 points, and the number of hours they spent studying per week. The scatterplot below displays the relationship between these two variables. a) What is the explanatory variable? GPA number of study hours per week b) What is the response variable? GPA number of study hours per week c) Describe the relationship between the variables. weak negative weak positive strong negative strong positive no relationship