First test and final exam. Refer to the previous exercise. Here are the data for the first test and the final exam:
(a) Find the correlation between these two variables.
(b) In Exercise 4.24 (page 169) we noted that the relationship between these two variables is weak. Does your calculation of the correlation support this statement? Explain your answer.
(c) Examine part (b) of the previous exercise. Does your calculation agree with your prediction?
Exercise 4.24
Relationship between first test and final exam. How strong is the relationship between the score on the first exam and the score on the final exam in an elementary statistics course? Here are data for eight students from such a course:
(a) Which variable should play the role of the explanatory variable in describing this relationship?
(b) Make a scatterplot and describe the relationship.
(c) Give some possible reasons why this relationship is so weak.