1. Which of the following sequences of heads and tails is more likely to have been
generated by tossing a fair coin?
A. HHTHTHTT
B. HHHHHHHH
C. Equally likely
2. A town is served by two hospitals. In the larger hospital about 45 babies are born
each day, and in the smaller hospital about 15 babies are born each day. As you know,
about 50% of all babies are boys. The exact percentage of baby boys, however, varies
from day to day. Sometimes it may be higher than 50%, sometime lower. For a
period of 1 year, each hospital recorded the days on which more than 60% of the
babies born were boys. Which hospital do you think recorded more such days?
A. larger
B. smaller
C. the same
3. The instructors in a flight school adopted a policy of consistent positive
reinforcement recommended by psychologists. They verbally reinforced each successful
execution of a flight maneuver. After some experience with this training approach, the
instructors claimed that contrary to psychological doctrine, high praise for good
execution of complex maneuvers typically result in a decrement of performance on the
next try. What should the psychologist say in response?
A sample of the residents of the Terra Nueva apartments shows this relationship
between living in apartments with foam insulation and having rashes:
4.
Rash
Insulation
Foam
Not Foam
Total
Absent
149
121
270
Present
120
63
183
Which cells of the table do you need to determine whether living in an apartment with
foam insulation is associated with a rash?
5. A plaintiffs’ law firm that specializes in toxic and related torts has a particular interest
in cancers putatively caused by strong electromagnetic fields. It has been monitoring 100
neighborhoods near large transformer stations. One of those neighborhoods recently
reported what appears to be a high incidence of brain tumors in children. After informing
several of the unfortunate families of their legal rights and being retained by them, the
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firm undertook a well-designed survey, which showed a statistically significant incidence
of brain tumors. Does this raise any concerns for you as a statistically-astute observer of
the legal system?
Answer sheet
1. __ A or __ B or __C
2. __ A or __ B or __C
3.
4. __ upper left
__ upper right
__ lower left
__ lower right
5.
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