. A large operator of timeshare complexes requires anyone interested in making a purchase to first
visit the site of interest. Historical data indicates that 20% of all potential purchasers select a day
visit, 50% choose a one-night visit, and 30% opt for a two-night visit. In addition, 10% of day
visitors ultimately make a purchase, 30% of night visitors buy a unit, and 20% of those visiting
for two nights decide to buy. Suppose a visitor is randomly selected and found to have bought a
timeshare. How likely is it that this person made a day visit? A one-night visit? A two-night visit?
74. Consider the following information about travelers (based partly on a recent Travelocity poll):
40% check work e-mail, 30% use a cell phone to stay connected to work, 25% bring a laptop with
them, 23% both check work e-mail and use a cell phone to stay connected, and 51% neither check
work e-mail nor use a cell phone to stay connected nor bring a laptop. Finally, 88 out of every
100 who bring a laptop check work e-mail, and 70 out of every 100 who use a cell phone to stay
connected also bring a laptop.
(a) What is the probability that a randomly selected traveler who checks work e-mail also uses a
cell phone to stay connected?
(b) What is the probability that someone who brings a laptop on vacation also uses a cell phone
to stay connected?
(c) If a randomly selected traveler checked work e-mail and brought a laptop, what is the
probability that s/he uses a cell phone to stay connected?