Critical Reasoning

The Ergonomic Society conducted a study that indicated that many people develop severe back problems during adulthood, and that virtually all such people who received chiropractic treatment showed great improvement. Therefore, in order to minimize the proportion of the population that suffers from back pain, the Ergonomic Society recommended that chiropractic treatment be directed toward those adults who suffer from severe back problems.

Which of the following is an assumption on which the argument depends?

A) Any person who receives chiropractic treatment for back pain may also benefit from other forms of treatment.
B) Large insurance carriers cover chiropractic care for back problems to a lesser degree than they do other medical treatments.
C) Individuals who receive chiropractic or other treatment prior to developing severe back problems are not less likely to develop back pain than those who do not.
D) Chiropractic treatment is more effective in treating severe back problems when utilized over a long period of time, as opposed to sporadically.
E) Severe back pain and other problems often cause individuals to miss workdays.

[spoiler]OA:C[/spoiler]

Prompt: many people-> severe back problems during adulthood ; All shows improvement after chiropractic treatment.

=> Conclusion: to minimize proportion of back pain -> chiropractic treatment for adults who suffer back pain.

A)Other form of treatment is irrelevant for this prompt (not an assumption that the argument depends on)
B) Whether large insurance cover or not (not relevant for our argument, not an assumption that the argument depends on)
C) Correct answer
D) Long vs sporadic period is not discussed in the prompt (not relevant)
E) missing workdays is not discussed in the prompt (not an assumption that the argument depends on)

it was easy to rule out answer A, B, D and E as they are all out of scope.

NEGATION of C: Individuals who receive chiropractic or other treatment prior to developing severe back are more likely to develop back pain than those who do not (this one weakens the conclusion, by showing that it is better to use the treatment as a preventive one rather than start curing people after they develop the problem)

So clearly the argument depends on the assumption that "Individuals who receive chiropractic or other treatment prior to developing severe back problems are not less likely to develop back pain than those who do not."

Hi joealam1.

First of all, this question is a little weak.

I guess we are supposed to gather that "the Ergonomic Society recommended that chiropractic treatment be directed toward those adults who suffer from severe back problems" means that the Ergonomic Society is recommending that such treatment not be directed at people who do not have back problems, but that that is the case is not entirely clear.

Meanwhile, your negation seems to contain an error.

joealam1 wrote:NEGATION of C: Individuals who receive chiropractic or other treatment prior to developing severe back are more likely to develop back pain than those who do not.

Did you mean to say "are less likely"?

Since C says

"Individuals who receive chiropractic or other treatment prior to developing severe back problems are not less likely to develop back pain ..."

the logical negation of C is

Individuals who receive chiropractic or other treatment prior to developing severe back problems are less likely to develop back pain ...

As you indicated, if C negated is true, then the argument is unsound, for C negated indicates that by directing chiropractic treatment at people who are not experiencing severe back problems, one could reduce the proportion of the population that will suffer from back pain.