Critical Reasoning

Deb: It's worrisome that 80% of the people in this country know at least one person who did not finish high school.

Erik: But the average person has about one hundred different acquaintances, so, even if the normal high school dropout rate is only 10%, most people will probably know at least one dropout.

Erik's argument relies on the assumption that:

A) The normal dropout rate has remained very stable over time.
B) The dropout rate varies little from region to region across the country.
C) The number of people who know a dropout is usually over 80% of the population.
D) The statistics cited by Deb don't overstate the fraction of the population that actually does know a high school dropout.
E) Being personally acquainted with a dropout causes more anxiety about the dropout problem than do the dropout statistics themselves.


What is the answer for this and please explain why other options are incorrect?

eitijan wrote:Deb: It's worrisome that 80% of the people in this country know at least one person who did not finish high school.

Erik: But the average person has about one hundred different acquaintances, so, even if the normal high school dropout rate is only 10%, most people will probably know at least one dropout.

Erik's argument relies on the assumption that:

A) The normal dropout rate has remained very stable over time.
B) The dropout rate varies little from region to region across the country.
C) The number of people who know a dropout is usually over 80% of the population.
D) The statistics cited by Deb don't overstate the fraction of the population that actually does know a high school dropout.
E) Being personally acquainted with a dropout causes more anxiety about the dropout problem than do the dropout statistics themselves.


What is the answer for this and please explain why other options are incorrect?

IMO C

Deb: It's worrisome that 80% of the people in this country know at least one person who did not finish high school.

Erik: But the average person has about one hundred different acquaintances, so, even if the normal high school dropout rate is only 10%, most people will probably know at least one dropout.

Erik's argument relies on the assumption that:

A) The normal dropout rate has remained very stable over time.

Erik's argument is based on the number of acquaintances that people have rather than on any particular dropout rate.

B) The dropout rate varies little from region to region across the country.

This seems to be the answer for the following reason.

Erik's argument is that since people have many acquaintances, even if the dropout rate were low, any given person would still likely know at least one person who has dropped out.

However, if the dropouts were concentrated in certain regions, then in order for 80% of people to know at least one dropout, maybe you would need more dropouts.

So I guess Erik's argument assumes that the dropouts are not concentrated in certain regions.

C) The number of people who know a dropout is usually over 80% of the population.

This misses the point. He is not basing his argument on what is usual.

D) The statistics cited by Deb don't overstate the fraction of the population that actually does know a high school dropout.

He is not depending on there being as many dropouts as Deb says there are.

E) Being personally acquainted with a dropout causes more anxiety about the dropout problem than do the dropout statistics themselves.

He is not basing his argument on the difference between anxiety caused by knowing a dropout and anxiety caused by the statistics.

So I guess that the answer is B. I am not totally convinced that the idea that Erik must be assuming what B says make sense, but there is some logic to the idea that Erik is assuming what B says, and there is no logical reason why Erik would be assuming what any of the other answer choices say.

Thanks a lot for the explanation and these resources. I will go through these videos, it would be of great help.