700+ Allergic tasting

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700+ Allergic tasting

by challenger63 » Tue Jan 15, 2013 1:20 am
In testing for food allergies, a false positive result occurs when a person is said to be allergic to a particular food when, in fact, they are not allergic to that food. A false negative result indicates that a person is not allergic to the food when, in fact, they are. To most accurately determine food allergies, a physician should use the test that gives the smallest percentage of false negative results.

Which of the following, if true, most supports the recommendation that is given above?

A. Some food allergies cause reactions severe enough to be life-threatening.
B. None of the tests for food allergies have lasting side effects.
C. In diagnosing food allergies it is important to be as thorough as possible, since most people with one known food allergy have other undiscovered food allergies.
D. The proportion of tests that do not provide a clear result is the same for all tests of food allergies
E. All tests for food allergies have the same proportion of false positive results

OA will be provided later.
Source: — Critical Reasoning |

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by Sam_hellboy » Tue Jan 15, 2013 3:30 am
IMO A..

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by Ankur87 » Tue Jan 15, 2013 6:08 am
challenger63 wrote:In testing for food allergies, a false positive result occurs when a person is said to be allergic to a particular food when, in fact, they are not allergic to that food. A false negative result indicates that a person is not allergic to the food when, in fact, they are. To most accurately determine food allergies, a physician should use the test that gives the smallest percentage of false negative results.

Which of the following, if true, most supports the recommendation that is given above?

A. Some food allergies cause reactions severe enough to be life-threatening.
B. None of the tests for food allergies have lasting side effects.
C. In diagnosing food allergies it is important to be as thorough as possible, since most people with one known food allergy have other undiscovered food allergies.
D. The proportion of tests that do not provide a clear result is the same for all tests of food allergies
E. All tests for food allergies have the same proportion of false positive results

OA will be provided later.
Confused between [spoiler][/spoiler]A and C[spoiler][/spoiler]

Others are out of scope.

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by zeza » Tue Jan 15, 2013 10:58 am
I would choose either A or C, but at the end I decided to go with A

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by GMATGuruNY » Tue Jan 15, 2013 12:33 pm
challenger63 wrote:In testing for food allergies, a false positive result occurs when a person is said to be allergic to a particular food when, in fact, they are not allergic to that food. A false negative result indicates that a person is not allergic to the food when, in fact, they are. To most accurately determine food allergies, a physician should use the test that gives the smallest percentage of false negative results.

Which of the following, if true, most supports the recommendation that is given above?

A. Some food allergies cause reactions severe enough to be life-threatening.
B. None of the tests for food allergies have lasting side effects.
C. In diagnosing food allergies it is important to be as thorough as possible, since most people with one known food allergy have other undiscovered food allergies.
D. The proportion of tests that do not provide a clear result is the same for all tests of food allergies
E. All tests for food allergies have the same proportion of false positive results

OA will be provided later.
This CR links the PERCENTAGE OF FALSE NEGATIVES to ACCURATELY DETERMINING FOOD ALLERGIES.
The assumption is that NO OTHER FACTORS -- particularly the PERCENTAGE OF FALSE POSITIVES -- should be considered when deciding which tests to use.
Answer choice E supports this assumption:
All tests for food allergies have the same proportion of false positive results.
If all tests have the SAME PROPORTION OF FALSE POSITIVES, then the percentage of false positives is irrelevant, supporting the conclusion that tests with the SMALLEST PERCENTAGE OF FALSE NEGATIVES will yield the most accurate results.

The correct answer is E.

None of the other answer choices strengthens the conclusion that tests with the smallest percentage of false negatives will be MORE ACCURATE than other types of tests.
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by Bill@VeritasPrep » Tue Jan 15, 2013 2:42 pm
This is a good example of a GMAT question that incorporates information about which you may have some knowledge or opinions. When you think "food allergy", you typically think about the potentially life-threatening ones, like peanuts. However, this specific stimulus has nothing about the severity of health consequences; we are only concerned with picking the most accurate test. We know that there are two ways for a test to be inaccurate: a false positive or a false negative. If all of the available tests give us the same proportion of false positives, that's not a good basis for choosing the most accurate test...they all perform the same. The only other option to choose the most accurate test is to look at the percentage of false negatives.
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by pavan.paone » Wed Jan 16, 2013 6:14 am
IMO A

If some food allergy is life threatening and if a test falsely identifies as negative ,then it will cause a serious problem.

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by GMATGuruNY » Wed Jan 16, 2013 8:02 am
pavan.paone wrote:IMO A

If some food allergy is life threatening and if a test falsely identifies as negative, then it will cause a serious problem.
While answer choice A explains why false negatives can cause problems, it does not support the conclusion that the test with the smallest percentage of false negatives will be the most ACCURATE.

Also, avoid the word SOME in strengthen/weaken questions.
Some could mean as few as one or two examples -- too few to strengthen or weaken the conclusion of a CR passage.
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by pavan.paone » Thu Jan 17, 2013 12:43 am
GMATGuruNY wrote:
pavan.paone wrote:IMO A

If some food allergy is life threatening and if a test falsely identifies as negative, then it will cause a serious problem.
While answer choice A explains why false negatives can cause problems, it does not support the conclusion that the test with the smallest percentage of false negatives will be the most ACCURATE.

Also, avoid the word SOME in strengthen/weaken questions.
Some could mean as few as one or two examples -- too few to strengthen or weaken the conclusion of a CR passage.
thanks for ur tip

after much thought process I figured out the answer must be D,Since it is the only one option which supports the conclusion

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by e-GMAT » Sat Jan 19, 2013 3:05 am
This is an interesting question, with a trap in option A.

Option A means that false negatives could lead to life threatening situations for people. Reading this, one feels as if this most strongly supports the conclusion that we should use a test with minimum false negatives.

While doing above reasoning, we are using our common sense that a test that leads to threatening situations is bad and we should have tests which avoid these conditions.

However, the conclusion, if read carefully, states that the objective is not to avoid life threatening situations or avoid damage to patients, it is to "to most accurately determine food allergies".

So, while option A seems good to our common sense, it does not provide any reason to strengthen the conclusion that a test with least false negatives will most accurately determine food allergies.

This strengthening is done by option E, which says that all tests have same proportion of false positives. This automatically means that one with lowest false negatives would have the best accuracy because

Accuracy = 100% - Proportion of False Positives - Proportion of False Negatives

Hope this helps :)

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by challenger63 » Sun Jan 20, 2013 6:16 am
OA E

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by Tommy Wallach » Sun Jan 20, 2013 2:51 pm
Another good thing to keep in mind here; the correct answer should relate to the argument as it was made. This argument is clearly all about false positives and negatives. (E) relates to that. (A) has absolutely nothing to do with either one.

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by BTG14 » Mon Jan 21, 2013 8:48 pm
Very good question.. I nearly took 10 mins to land Option E as my answer.