The report "Twitter in Higher Education: Usage Habits and Trends of Today's
College Faculty" describes a survey of nearly 2000 college faculty. The report
indicates the following:
\(30.7 \%\) reported that they use Twitter, and \(69.3 \%\) said that they do not
use Twitter. Of those who use Twitter, \(39.9 \%\) said they sometimes use
Twitter to communicate with students. Of those who use Twitter, \(27.5 \%\) said
that they sometimes use Twitter as a learning tool in the classroom.
Consider the chance experiment that selects one of the study participants at
random.
a. Two of the percentages given in the problem specify unconditional
probabilities, and the other two percentages specify conditional
probabilities. Which are conditional probabilities? How can you tell?
b. Suppose the following events are defined:
\(T=\) event that selected faculty member uses Twitter
\(C=\) event that selected faculty member sometimes uses Twitter to communicate
with students
\(L=\) event that selected faculty member sometimes uses Twitter as a learning
tool in the classroom
Use the given information to determine the following probabilities:
i. \(P(T)\)
iii. \(P(C \mid T)\)
ii. \(P\left(T^{C}\right)\)
iv. \(\quad P(L \mid T)\)
c. Construct a hypothetical 1000 table using the given probabilities and use
the information in the table to calculate \(P(C),\) the probability that the
selected study participant sometimes uses Twitter to communicate with
students.
d. Construct a hypothetical 1000 table using the given probabilities and use
the information in the table to calculate the probability that the selected
study participant sometimes uses Twitter as a learning tool in the classroom.