# Critical Reasoning: Conclusion Strengthening Questions

Brand Zzzoom released a running shoe with a shock-absorbing sole developed using a new foam polymer that reduces muscle fatigue in the legs of runners. The density of the foam, however, results in the overall shoe weight being slightly heavier than most high quality running shoes. Professional runners who welcome the use of Zzzoom's new shoe will definitely experience an improved performance in their runs.

Which of the following, if true, most seriously strengthens the argument?

Incorrect.

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This answer choice contradicts Premise B, which explicitly states the extra weight in the show is a result of the foam density. Therefore, it is irrelevant to the argument.

Incorrect.

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Focus on the conclusion. We're trying to find a statement that will support it. This answer choice seems to weaken the conclusion by giving importance to the weight of the shoe.

Incorrect.

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Although this answer choice supports the Zzzoom shoe, it does not actually support the argument's conclusion. The conclusion is about the improved performance of the runners and not about the effects they will experience much later in life.

Incorrect.

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This answer choice introduces the topic of aerodynamics into the discussion. Since we know nothing about this aspect in Zzzoom's shoe, we cannot refer to it as a factor that strengthens the conclusion.

Very well done!

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Although the Zzzoom shoe is slightly heavier, according to the research in this answer choice, shock-absorption is a more important factor in running performance than weight (or any other factor): 72% of a runner's energy is lost on impact with the road. Because the Zzzoom shoes offers better shock-absorption rather than lighter weight, this answer choice strengthens the conclusion that it will improve a runner's performance.

The overall shoe weight is affected not only by the density of the sole but also by the materials used in the other components of the shoe.
Since the muscles lifting the leg also lift the shoe, a lighter shoe is likely to produce better results than a heavier one.
Research shows that 72% of a runner's muscular energy is expired on impact with the running surface.
Too light a running shoe can result in the emergence of knee problems during old age.
Aerodynamics can be critical in the optimization of a professional running shoe's performance.