TABLE 4-2
An alcohol awareness task force at a Big-Ten university sampled 200 students after the midterm to ask them whether they went bar hopping the weekend before the midterm or spent the weekend studying,and whether they did well or poorly on the midterm.The following result was obtained.
-Referring to Table 4-2,the events "Did Well on Midterm" and "Studying for Exam" are
A)dependent.
B)mutually exclusive.
C)collectively exhaustive.
D)None of the above.

Question

TABLE 4-2
An alcohol awareness task force at a Big-Ten university sampled 200 students after the midterm to ask them whether they went bar hopping the weekend before the midterm or spent the weekend studying,and whether they did well or poorly on the midterm.The following result was obtained. 
-Referring to Table 4-2,the events "Did Well on Midterm" and "Studying for Exam" are
A)dependent. 
B)mutually exclusive. 
C)collectively exhaustive. 
D)None of the above.

Quizplus · Accepted Answer

The events "Did Well on Midterm" and "Studying for Exam" are likely dependent, as it is reasonable to assume that students who studied for the exam were more likely to do well on it. However, we cannot definitively conclude dependence without additional information about the students' study habits and other relevant factors. Mutually exclusive events cannot occur at the same time, which is not the case here as some students who studied may also have gone bar hopping. Collectively exhaustive events collectively encompass all possible outcomes, which is not the case here as there are other possible activities (besides bar hopping and studying) that students could have done that weekend.

TABLE 4-2 An Alcohol Awareness Task Force at a Big-Ten University Sampled