Relationship between second test and final exam. Refer to the previous exercise. Here are the data for the second test and the final exam for the same students:
(a) Explain why you should use the second-test score as the explanatory variable.
(b) Make a scatterplot and describe the relationship.
(c) Why do you think the relationship between the second-test score and the final-exam score is stronger than the relationship between the first-test score and the final-exam score?