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.

$\begin{array}{l|cc}
& \text {Did Well on Midterm} & \text {Did Poorly on Midterm} \
\hline\text {Studying for Exam }& 80 & 20 \
\text {Went Bar Hopping} & 30 & 70
\end{array}$

-Referring to Table 4-2, the events "Did Well on Midterm" and "Did Poorly on Midterm" are
A) collective exhaustive.
B) statistically dependent.
C) mutually exclusive.
D) all 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.

$\begin{array}{l|cc} 
& \text {Did Well on Midterm} & \text {Did Poorly on Midterm} \
\hline\text {Studying for Exam }& 80 & 20 \
\text {Went Bar Hopping} & 30 & 70
\end{array}$

-Referring to Table 4-2, the events "Did Well on Midterm" and "Did Poorly on Midterm" are
A) collective exhaustive.
B) statistically dependent.
C) mutually exclusive.
D) all of the above

Quizplus · Accepted Answer

The events "Did Well on Midterm" and "Did Poorly on Midterm" are mutually exclusive because a student cannot do both well and poorly on the midterm. They are also collective exhaustive because every student must have either done well or poorly on the midterm. Finally, they are statistically dependent because the probability of doing well on the midterm is different for students who studied for the exam than for students who went bar hopping.

TABLE 4-2 an Alcohol Awareness Task Force at a Big-Ten

TABLE 4-2
an Alcohol Awareness Task Force at a Big-Ten