Scientists investigating a rare metabolic disorder

Question

Scientists investigating a rare metabolic disorder hypothesized that d obesity was a predisposing factor in the development of the disease. A study of twenty patients found that, on average, the patients were close to the normal weight for their height.

Before concluding that obesity is not a predisposing factor, the researchers would find the answer to which of the following questions most useful?

A. Are the patients above or below normal height?
B. Were any of the patients underweight when the disorder was diagnosed?
C. Does weight loss reduce the severity of the symptoms?
D. Have the patients always been close to the normal weight for their heights?
E. How many of the patients had obese parents?

Need explanation............. 
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mikemcgarry · Answer

Dear mun23

A few questions.

"... hypothesized that d obesity ...."
Is that "d" just a misprint, or does it denote some category of obesity that might be relevant to the question?

".... A study of twenty patients found ..."
Were these 20 patients all of whom were know to have the disorder? Twenty patients known to have a predisposition to the order? What was the selection criterion for these 20 patients?

Mike :-)

Bafflepitch · Answer

A) - Their height has nothing to do with the issue since their weight is adjusted based on their height in the study "the patients were close to the normal weight for their height"
B) - Being the opposite of obesity when diagnosed does not rule out that obesity could be a predisposing factor. Even if this one was true, then you could say being underweight or overweight could be a predisposing factor. 
C) - Even if weight loss reduces the symptoms, they already have the disease. The scientists are concerned about a predisposing factor, not reducing symptoms. Irrelevant.
D) - This one is correct. The scientists are looking at the patient's current weight, not what weight they were before being diagnosed, which is not discussed in this article. For example, they could all have been 300 lbs a year ago when diagnosed, but treatment for this disease and side effects could have caused them to all be close to normal weight now. 
E) - Irrelevant. The parent's weight is not what is of concern, but the patient's weight. The parent's weight could still be an issue, but that is not what the question is concerned about.

jlgdr · Answer

Mike I agree with you, there's something fishy with this question, let's wait for someone to confirm these doubts
Cheers
J

spetznaz · Answer

Can you please specify the source ?

mikemcgarry · Answer

Dear spetznaz , I'm happy to respond. :-)

I did a web search and found a company named "Major Tests." The question appears there, so I assume folks at this company are the authors. https://www.majortests.com/gmat/critical ... ing_test03 I have never heard of this company before, but this question doesn't really impress me. Especially with GMAT Verbal content, it is very important to work primarily with official material and with the material of high quality GMAT preparation companies. MGMAT and Magoosh have excellent questions and many Veritas questions are very good. Some other companies have very questionable material, and working with questionable GMAT Verbal practice questions won't necessarily help you. Again, I know almost nothing about this particular company. I hope this helps. Mike :-)

spetznaz · Answer

Hey Mike ! Thanks for the clarification

wadhwakaran · Answer

Premise: Scientists were investigating a rare metabolic disorder

Scientists' Hypothesis: Obesity was a predisposing factor in the development of the disease.

Study of 20 students: Patients were close to the normal weight for their height.

Aim: to prove obesity is not a predisposing factor

What if the weight of the students were lost later on after contracting the rare metabolic disorder meaning thereby that obesity is still a predisposing factor in development of disease.

A. Are the patients above or below normal height?  No 
B. Were any of the patients underweight when the disorder was diagnosed? No 
C. Does weight loss reduce the severity of the symptoms? No 
D. Have the patients always been close to the normal weight for their heights?  Yes in line with the thinking above 
E. How many of the patients had obese parents? No

egmat · Answer

Hi there,

Let's break this question down step by step.

The Setup: 
- Scientists hypothesized that obesity is a predisposing factor for a rare metabolic disorder.
- They studied  20  patients and found they were currently close to normal weight.
- They're about to conclude: obesity is NOT a predisposing factor.

The Question asks:  What information would be most useful before drawing that conclusion?

The Key Flaw in Their Reasoning: 
The researchers are looking at what patients weigh NOW. But a "predisposing factor" means something that existed BEFORE the disease developed. These are  two completely different time periods!

Imagine this scenario: All  20  patients were obese five years ago, then developed the disorder, and the disorder itself (or its treatment) caused them to lose weight. They'd now be normal weight, but obesity absolutely WAS a predisposing factor.

This is exactly why Answer D is correct:  "Have the patients always been close to the normal weight for their heights?" If the answer is YES (they were always normal weight), then it's fair to say obesity wasn't a predisposing factor. If the answer is NO (they used to be obese), then the conclusion falls apart. Either way, this question gives the researchers the most critical missing information.

Why the other answers fail: 
-  A  (height): Irrelevant — the study already accounts for height by using "normal weight for their height."
-  B  (underweight patients): Knowing about underweight patients doesn't help evaluate whether obesity was a factor.
-  C  (weight loss reducing symptoms): This is about treatment, not about what predisposed them to the disease.
-  E  (obese parents): Parental obesity is a separate factor from the patients themselves being obese.

Key Takeaway:  In CR questions involving medical studies, always check whether the evidence measures the right time period. Current data cannot automatically tell you about past conditions, and "predisposing" factors by definition exist before the condition develops.

Common mistake: Confusing what patients weigh NOW with what they weighed BEFORE developing the condition — this is a classic temporal mismatch trap.

Answer: D

Scientists investigating a rare metabolic disorder

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Scientists investigating a rare metabolic disorder

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