LSAT Explanation PT 36, S1, Q25: A 1991 calculation was made to

LSAT Question Stem

Which one of the following, if true and not taken into account by the calculation, most seriously weakens the argument? 

Logical Reasoning Question Type

This is a Weaken question. 

Correct Answer

The correct answer to this question is C. 

LSAT Question Complete Explanation

The passage presents an argument that people's voluntary choice not to exercise places a significant burden on society, citing a 1991 calculation that determined sedentary individuals bear an average lifetime cost of $1,650 beyond ordinary health-care costs. In this Weaken question, we are asked to identify the statement that, if true and not considered in the calculation, would most seriously undermine the argument.

Let's analyze the argument structure:

Premise: A 1991 calculation found that sedentary people bear an average lifetime cost of $1,650 beyond ordinary health-care costs.

Conclusion: People's voluntary choice not to exercise places a significant burden on society.

An "Evaluate" question for this argument could be: "Are all sedentary individuals voluntarily choosing not to exercise?"

Now, let's discuss the answer choices:

a) This answer choice tells us that many people who work in physically demanding jobs do not choose to engage in regular exercise outside of work. However, these people are not living a sedentary life, so this statement does not weaken the conclusion about the burden caused by voluntary choice not to exercise.

b) The fact that exercise is often omitted from doctor-patient discussions does not weaken the conclusion. The argument is about the burden caused by people's choice not to exercise, and this statement does not provide any information about the relationship between sedentary lifestyles and the burden on society.

c) Correct answer. This statement introduces an alternate cause for sedentary lifestyles: physical conditions that predispose a person to adopt a sedentary life. This weakens the argument because it suggests that not all sedentary lifestyles are the result of voluntary choice, and thus the burden on society might not be solely due to people's choices not to exercise.

d) This answer choice focuses on the variations in exercise choices among individuals who do exercise regularly. It does not address the relationship between sedentary lifestyles and the burden on society, so it does not weaken the conclusion.

e) This statement provides additional benefits of regular exercise but does not weaken the argument about the burden caused by people's choice not to exercise. It is a premise-booster rather than a weakener.

In conclusion, the correct answer is C, as it introduces an alternate cause for sedentary lifestyles, calling into question the argument's conclusion that the burden on society is due to people's voluntary choice not to exercise.