Suppose for each student in a large statistics class, you record how far she/he sits from the teacher during a particular class session and how much time she/he spends on her/his computer during class. (No explanations are necessary for the following questions.)

a. Students who sit closer to the teacher tend to use their computer less in class. Would you expect the correlation coefficient between distance and computer usage time to be positive, negative, or close to zero?

b. The correlation coefficient between distance and computer usage time turns out to be close to -1. Would that prove that sitting close to the teacher causes students to spend more time using their computer in class?

c. There is really no association between distance and computer usage time. Would you expect the correlation coefficient to be positive, negative, or close to zero?

d. There is really no association between distance and computer usage time. Is it still possible to calculate a correlation coefficient?