Self-study
Statistician: A financial magazine claimed that its survey of its subscribers showed that North Americans are more concerned about their personal finances than about politics. ███ ████████ ████ ██████ ██ ███ █████ █████ █████ ████████ ██ ███ ███ ██ ███████ ███████ ████ ████████ ██ ███████ ███████ █████ ███ ███████ ██ ███ ████████ ███ █ ██████████████ ███████ █████ █████ ██ ██████ ██ ██ █████████ █████ ███ ██████████ █████ ██ ███ ██████████ ███████
Summarize Argument
The statistician claims there’s reason to be skeptical about the magazine’s claim that North Americans are more concerned with finances than politics. Why? Because a question on the survey was biased and because subscribers to the magazine might poorly represent North Americans in general.
Notable Assumptions
The statistician assumes conclusions based on a survey with a self-selecting sample and a biased question should be received skeptically. He assumes the survey question he quotes is biased in a way that could affect the conclusion based on the survey’s results.
15.
Each of the following, if █████ █████ ██████████ ███ ██████████████ ████████ ███████
a
The credibility of ███ ████████ ███ ████ ██████ ████ ████████ ██ █ ██████ ██ ██████████
This is another reason to view the survey’s results with skepticism. It suggests the magazine has been accused of being careless or insincere, which doesn’t prove the magazine’s conclusion wrong, but does give a reason to be skeptical of it.
b
The conclusions drawn ██ ████ ████████ ███████ ████ ██████████ ████ ██████████
This is another reason to view the magazine’s conclusion with skepticism. It suggests magazine surveys in general are unreliable, which doesn’t prove this magazine’s conclusion is false, but gives a reason to be skeptical about it.
c
Other surveys suggest ████ █████ █████████ ███ ████ ██ █████████ █████ ████████ ██ ████ ███ █████ █████████
This introduces new evidence that conflicts with the magazine’s conclusion, giving more reason to doubt that conclusion.
d
There is reason ██ ██ █████████ █████ ███ ███████ ██ ███████ ████ ███ ██████ ███ █████████████████
This makes concrete the statistician’s assumption that a survey with an unrepresentative sample and a biased question should be viewed skeptically.
e
Other surveys suggest ████ █████ █████████ ███ █████████ ███ ████ ████ ████████ ███ █████████ ███ ████ ████ ██████ ███████
This is irrelevant. Neither the magazine nor the statistician assumes politics and personal finance are the only two issues North Americans care about. Concern about a third issue gives no reason to doubt the magazine’s conclusion, which compares interest in the two issues only.