Post by hakutsuru on Apr 17, 2008 8:59:29 GMT -8
Dr. Egbert is the world’s foremost researcher on the subject of cooties in children. In an effort to better understand this dreaded disease he decides to conduct several studies.
In the first study, he surveys a random sample of elementary school students.
He found that 80 students suffering from booger-breath had the cooties. However, only 20 students with the cooties didn’t have booger-breath. 40 students suffered from just booger-breath. Only 10 students were found to have neither.
From this data Dr. Egbert can reasonably conclude that:
a) Booger-breath is a symptom of the cooties.
b) Booger-breath is not a symptom of the cooties.
c) We cannot tell whether booger-breath is a symptom of the cooties.
Dr. Egbert does another study, this time to determine the incidence of the cooties. He finds that 40% of fourth graders at a particular school have the cooties. He also finds that about 60% of the students tested pick their noses and eat the resulting boogers. Dr. Egbert can reasonably conclude that:
a) Half the students in the class pick their nose and eat it and have the cooties.
b) Most of the students pick their nose and eat it and have the cooties.
c) Not many students pick their nose and eat it and have the cooties.
d) None of the students pick their nose and eat it and have the cooties.
Finally Dr. Egbert wants to test whether a particular hypothesis is true. He postulates that whenever a child has the cooties they also suffer from stinky-britches. He knows the following:
a) Paul has the cooties.
b) Mary does not have the cooties.
c) Connie has stinky-britches.
d) Miguel does not have stinky-britches.
Dr. Egbert can test any student for either the cooties or stinky-britches. What student or students does he need to test in order to be certain that, at least for the four students surveyed, the hypothesis is true?
How do these elementary logic puzzles about an imaginary disease pertain to real diseases such as Lyme or HIV? Certainly we can substitute real diseases, symptoms, behaviors, and statistics for any of the make-believe cases. Unfortunately, Lyme presents us with far more difficult puzzles.
Feel free to post your answers.
In the first study, he surveys a random sample of elementary school students.
He found that 80 students suffering from booger-breath had the cooties. However, only 20 students with the cooties didn’t have booger-breath. 40 students suffered from just booger-breath. Only 10 students were found to have neither.
From this data Dr. Egbert can reasonably conclude that:
a) Booger-breath is a symptom of the cooties.
b) Booger-breath is not a symptom of the cooties.
c) We cannot tell whether booger-breath is a symptom of the cooties.
Dr. Egbert does another study, this time to determine the incidence of the cooties. He finds that 40% of fourth graders at a particular school have the cooties. He also finds that about 60% of the students tested pick their noses and eat the resulting boogers. Dr. Egbert can reasonably conclude that:
a) Half the students in the class pick their nose and eat it and have the cooties.
b) Most of the students pick their nose and eat it and have the cooties.
c) Not many students pick their nose and eat it and have the cooties.
d) None of the students pick their nose and eat it and have the cooties.
Finally Dr. Egbert wants to test whether a particular hypothesis is true. He postulates that whenever a child has the cooties they also suffer from stinky-britches. He knows the following:
a) Paul has the cooties.
b) Mary does not have the cooties.
c) Connie has stinky-britches.
d) Miguel does not have stinky-britches.
Dr. Egbert can test any student for either the cooties or stinky-britches. What student or students does he need to test in order to be certain that, at least for the four students surveyed, the hypothesis is true?
How do these elementary logic puzzles about an imaginary disease pertain to real diseases such as Lyme or HIV? Certainly we can substitute real diseases, symptoms, behaviors, and statistics for any of the make-believe cases. Unfortunately, Lyme presents us with far more difficult puzzles.
Feel free to post your answers.
?? Do we believe his/her conclusions?