Inference doubt

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gauravgundal: Master | Next Rank: 500 Posts; Posts: 199; Joined: Mon Apr 06, 2009 4:15 am; Location: India; Thanked: 13 times

by gauravgundal » Wed Oct 06, 2010 2:38 am

Until recently, the scholarly consensus was that few marine species are approaching extinction. Closer examination of marine species near the island of West Indies, however, revealed many factors, such as climate change and Â…fishing, that may be contributing to the extinction of species thought to be safe. The rate of extinction of marine species may be just as high as that of non-marine species, but the lack of systematic sampling has disguised the trend.

Which of the following is most strongly supported by the statements given?

(A) There are many marine species near West Indies that are nearing extinction.
(B) Scholars who analyze the possible extinction of non-marine species rely on systematic sampling to determine which species are endangered.
(C) If systematic sampling were a more common practice in marine environments, there would likely be more evidence supporting the hypothesis that many marine species are approaching extinction.
(D) The threat to marine species near West Indies is more severe than the threat to marine species whose habitats are elsewhere.
(E) If the rate of climate change were arrested and Â…fishing were curtailed, the rate of extinction of marine species would
fall to a level far below that of non-marine species.

[spoiler]OA: C[/spoiler]
IMO: B

B is incorrect because it talks about the information for non-marine species, and the argument doesn't show any co-relation between marine and non-marine species.

But I am really confused about C,the argument states about the few marine species then wny does is conclude about many marine species
Even if the rate of extinction is high. The argument doesn't specify 'high'.High can 0.2 or 100000.

expert please guide me to get to the root of this argument.

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Source: Beat The GMAT — Critical Reasoning | Wed Oct 06, 2010 2:38 am

bubbliiiiiiii: Legendary Member; Posts: 979; Joined: Tue Apr 14, 2009 1:38 amFollowed by: 12 members; Location: Hyderabad, India; Thanked: 49 times; GMAT Score:700

by bubbliiiiiiii » Wed Oct 06, 2010 3:24 am

Until recently, the scholarly consensus was that few marine species are approaching extinction. Closer examination of marine species near the island of West Indies, however, revealed many factors, such as climate change and Â…fishing, that may be contributing to the extinction of species thought to be safe. The rate of extinction of marine species may be just as high as that of non-marine species, but the lack of systematic sampling has disguised the trend.

Which of the following is most strongly supported by the statements given?

(A) There are many marine species near West Indies that are nearing extinction.
This is given in the passage - ruled out.
(B) Scholars who analyze the possible extinction of non-marine species rely on systematic sampling to determine which species are endangered. The passage states about the lack of systematic sampling indicating that systematic sampling was not used which disguised the trend. On the contrary, this option refers about relying on systematic sampling. Thus, ruled out.
(C) If systematic sampling were a more common practice in marine environments, there would likely be more evidence supporting the hypothesis that many marine species are approaching extinction. This is appropriately supported by the stimulus since it identifies that the systematic sampling was not effectively used and talks about the identified trend if the SA was properly used
(D) The threat to marine species near West Indies is more severe than the threat to marine species whose habitats are elsewhere. - out of scope - ruled out.
(E) If the rate of climate change were arrested and Â…fishing were curtailed, the rate of extinction of marine species would
fall to a level far below that of non-marine species. out of scope - ruled out.

Hope it helps!

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diebeatsthegmat: Legendary Member; Posts: 1119; Joined: Fri May 07, 2010 8:50 amFollowed by: 3 members; Thanked: 29 times

by diebeatsthegmat » Wed Oct 06, 2010 3:12 pm

gauravgundal wrote:Until recently, the scholarly consensus was that few marine species are approaching extinction. Closer examination of marine species near the island of West Indies, however, revealed many factors, such as climate change and Â…fishing, that may be contributing to the extinction of species thought to be safe. The rate of extinction of marine species may be just as high as that of non-marine species, but the lack of systematic sampling has disguised the trend.

Which of the following is most strongly supported by the statements given?

(A) There are many marine species near West Indies that are nearing extinction.
(B) Scholars who analyze the possible extinction of non-marine species rely on systematic sampling to determine which species are endangered.
(C) If systematic sampling were a more common practice in marine environments, there would likely be more evidence supporting the hypothesis that many marine species are approaching extinction.
(D) The threat to marine species near West Indies is more severe than the threat to marine species whose habitats are elsewhere.
(E) If the rate of climate change were arrested and Â…fishing were curtailed, the rate of extinction of marine species would
fall to a level far below that of non-marine species.

[spoiler]OA: C[/spoiler]
IMO: B

B is incorrect because it talks about the information for non-marine species, and the argument doesn't show any co-relation between marine and non-marine species.

But I am really confused about C,the argument states about the few marine species then wny does is conclude about many marine species
Even if the rate of extinction is high. The argument doesn't specify 'high'.High can 0.2 or 100000.

expert please guide me to get to the root of this argument.

C here too,

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ronaldramlan: Senior | Next Rank: 100 Posts; Posts: 87; Joined: Mon Jun 30, 2008 5:44 amFollowed by: 2 members; Thanked: 14 times

by ronaldramlan » Sun Oct 17, 2010 1:48 am

gauravgundal wrote:Until recently, the scholarly consensus was that few marine species are approaching extinction. Closer examination of marine species near the island of West Indies, however, revealed many factors, such as climate change and Â…fishing, that may be contributing to the extinction of species thought to be safe. The rate of extinction of marine species may be just as high as that of non-marine species, but the lack of systematic sampling has disguised the trend.

Which of the following is most strongly supported by the statements given?

(A) There are many marine species near West Indies that are nearing extinction.
(B) Scholars who analyze the possible extinction of non-marine species rely on systematic sampling to determine which species are endangered.
(C) If systematic sampling were a more common practice in marine environments, there would likely be more evidence supporting the hypothesis that many marine species are approaching extinction.
(D) The threat to marine species near West Indies is more severe than the threat to marine species whose habitats are elsewhere.
(E) If the rate of climate change were arrested and Â…fishing were curtailed, the rate of extinction of marine species would
fall to a level far below that of non-marine species.

[spoiler]OA: C[/spoiler]
IMO: B

B is incorrect because it talks about the information for non-marine species, and the argument doesn't show any co-relation between marine and non-marine species.

But I am really confused about C,the argument states about the few marine species then wny does is conclude about many marine species
Even if the rate of extinction is high. The argument doesn't specify 'high'.High can 0.2 or 100000.

expert please guide me to get to the root of this argument.

C is just another way of saying what was stated in the last sentence of the passage ("The rate of extinction of marine species may be just as high as that of non-marine species, but the lack of systematic sampling has disguised the trend.").
You are correct that the argument initially mentions that only few marine species are considered endangered. But, the author went on to say that the rate of extinction of marine species might reach that of non-marine species, a rate considered high. So, the author already disputes the common consensus stated in the beginning of the passage.

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Dangerous Dude: Senior | Next Rank: 100 Posts; Posts: 38; Joined: Sat Oct 16, 2010 10:27 pm

by Dangerous Dude » Sun Oct 17, 2010 2:08 am

B is out of score.. No where mentioned of technology used with non marine specis...

C is correct...

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rooster: Senior | Next Rank: 100 Posts; Posts: 44; Joined: Wed Aug 25, 2010 12:23 am; Thanked: 6 times

by rooster » Wed Oct 20, 2010 9:05 pm

gauravgundal wrote:Until recently, the scholarly consensus was that few marine species are approaching extinction. Closer examination of marine species near the island of West Indies, however, revealed many factors, such as climate change and Â…fishing, that may be contributing to the extinction of species thought to be safe. The rate of extinction of marine species may be just as high as that of non-marine species, but the lack of systematic sampling has disguised the trend.

B is out of scope, that's for sure. The part about non-marine species is used to throw the reader off.

What you need to look for in this is something that supports these statements, and a minor hint is that the last sentence is not a conclusion, but another statement. With that said, C fits what they are trying to conclude, as most of you have already mentioned...

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mundasingh123: Legendary Member; Posts: 2330; Joined: Fri Jan 15, 2010 5:14 amFollowed by: 26 members; Thanked: 56 times

by mundasingh123 » Sun Jan 16, 2011 11:00 pm

i Can U pls reveal the source

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mundasingh123: Legendary Member; Posts: 2330; Joined: Fri Jan 15, 2010 5:14 amFollowed by: 26 members; Thanked: 56 times

by mundasingh123 » Mon Jan 17, 2011 12:03 am

rooster wrote:
gauravgundal wrote:Until recently, the scholarly consensus was that few marine species are approaching extinction. Closer examination of marine species near the island of West Indies, however, revealed many factors, such as climate change and Â…fishing, that may be contributing to the extinction of species thought to be safe. The rate of extinction of marine species may be just as high as that of non-marine species, but the lack of systematic sampling has disguised the trend.
B is out of scope, that's for sure. The part about non-marine species is used to throw the reader off.

What you need to look for in this is something that supports these statements, and a minor hint is that the last sentence is not a conclusion, but another statement. With that said, C fits what they are trying to conclude, as most of you have already mentioned...

The last statement may as well be taken as an explanation for the change in stance that the Researchers had taken initially on the extinction of Marine species

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prachich1987: Legendary Member; Posts: 752; Joined: Sun Sep 12, 2010 2:47 amFollowed by: 10 members; Thanked: 20 times; GMAT Score:700

by prachich1987 » Mon Jan 17, 2011 12:11 am

gauravgundal wrote:Until recently, the scholarly consensus was that few marine species are approaching extinction. Closer examination of marine species near the island of West Indies, however, revealed many factors, such as climate change and Â…fishing, that may be contributing to the extinction of species thought to be safe. The rate of extinction of marine species may be just as high as that of non-marine species, but the lack of systematic sampling has disguised the trend.

Which of the following is most strongly supported by the statements given?

(A) There are many marine species near West Indies that are nearing extinction.
(B) Scholars who analyze the possible extinction of non-marine species rely on systematic sampling to determine which species are endangered.
(C) If systematic sampling were a more common practice in marine environments, there would likely be more evidence supporting the hypothesis that many marine species are approaching extinction.
(D) The threat to marine species near West Indies is more severe than the threat to marine species whose habitats are elsewhere.
(E) If the rate of climate change were arrested and Â…fishing were curtailed, the rate of extinction of marine species would
fall to a level far below that of non-marine species.

[spoiler]OA: C[/spoiler]
IMO: B

B is incorrect because it talks about the information for non-marine species, and the argument doesn't show any co-relation between marine and non-marine species.

But I am really confused about C,the argument states about the few marine species then wny does is conclude about many marine species
Even if the rate of extinction is high. The argument doesn't specify 'high'.High can 0.2 or 100000.

expert please guide me to get to the root of this argument.

Please advise source of the question.
It is very important for everone to know the source of the question.
Please read below a message from one of the MGMAT expert "Whitney Garner"

1) If you don't know the source, then you don't know whether you are compromising your future practice tests. What if the question is from the practice test you're about to take and now you see a question that you've already seen before? When that happens, it can blow the validity of your whole test! (Not if it happens just once, of course, but what if it happens multiple times?)

2) If you're taking a practice test and do see a question you've seen before, you'll probably answer it more quickly. This will give you a false sense of timing security because you now have a little more time... but that situation will NEVER be replicated on the real test.

3) The source might be bad. Do you want to study from a bad source? I don't!
_____

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Adam@Knewton: GMAT Instructor; Posts: 132; Joined: Mon Jan 10, 2011 12:26 pmFollowed by: 37 members; Location: New York City; Thanked: 68 times; GMAT Score:780

by Adam@Knewton » Mon Jan 17, 2011 1:36 pm

The word "many" does not have a formal logical definition, the way "most" implies "more than half" and "some" implies "more than zero." To summarize the statements given here:

1) Some claim that few marine species are going extinct...
2)...but they're wrong [So, it must be that "more than few" are going extinct].
3) The reason they're wrong is due to a lack of systematic sampling.

Inference --> If they used systematic sampling, they'd see "more than few" marine species going extinct. "Many," an intentionally vague term, often shows up in Inference questions like this, much like the words "can" or "about" which similarly are left open to many interpretations and thus are almost always properly inferrable.

As for B, you're not crazy to notice it; it's tempting because we're told that non-marine extinction estimates are higher and that systematic sampling would raise our marine extinction estimates to comparable levels. However, as many have pointed out above, we can't know for sure that the non-marine extinction estimates are in fact based upon systematic sampling. It seems very likely that they are, but "very likey" on GMAT Inference questions is synonymous with "wrong."

rooster wrote:What you need to look for in this is something that supports these statements, and a minor hint is that the last sentence is not a conclusion, but another statement. With that said, C fits what they are trying to conclude, as most of you have already mentioned...

Be careful here! This is an Inference, not a Strengthener, question. This is a common mistake -- they're not asking you to "support the Argument above," as in a Strengthener question, but in fact to use the statatements above TO support the correct answer. This owrding is important since there is no Conclusion here at all, only a set of Evidence.[

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nipunkathuria: Senior | Next Rank: 100 Posts; Posts: 43; Joined: Tue Dec 29, 2009 6:40 pm; Thanked: 2 times

by nipunkathuria » Mon Jan 17, 2011 4:58 pm

AdamKnewton wrote:The word "many" does not have a formal logical definition, the way "most" implies "more than half" and "some" implies "more than zero." To summarize the statements given here:

1) Some claim that few marine species are going extinct...
2)...but they're wrong [So, it must be that "more than few" are going extinct].
3) The reason they're wrong is due to a lack of systematic sampling.

Inference --> If they used systematic sampling, they'd see "more than few" marine species going extinct. "Many," an intentionally vague term, often shows up in Inference questions like this, much like the words "can" or "about" which similarly are left open to many interpretations and thus are almost always properly inferrable.

As for B, you're not crazy to notice it; it's tempting because we're told that non-marine extinction estimates are higher and that systematic sampling would raise our marine extinction estimates to comparable levels. However, as many have pointed out above, we can't know for sure that the non-marine extinction estimates are in fact based upon systematic sampling. It seems very likely that they are, but "very likey" on GMAT Inference questions is synonymous with "wrong."

rooster wrote:What you need to look for in this is something that supports these statements, and a minor hint is that the last sentence is not a conclusion, but another statement. With that said, C fits what they are trying to conclude, as most of you have already mentioned...

Be careful here! This is an Inference, not a Strengthener, question. This is a common mistake -- they're not asking you to "support the Argument above," as in a Strengthener question, but in fact to use the statatements above TO support the correct answer. This owrding is important since there is no Conclusion here at all, only a set of Evidence.[

nice one....thanks for explaining the difference in what they re asking..(inference vs strengthening)

Back !!!

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ahnan: Junior | Next Rank: 30 Posts; Posts: 12; Joined: Wed Apr 14, 2010 6:22 am

by ahnan » Tue Jan 18, 2011 12:17 am

AdamKnewton, can u tell us your method to deal with this type of question?

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mundasingh123: Legendary Member; Posts: 2330; Joined: Fri Jan 15, 2010 5:14 amFollowed by: 26 members; Thanked: 56 times

by mundasingh123 » Tue Jan 18, 2011 8:47 am

ahnan wrote:AdamKnewton, can u tell us your method to deal with this type of question?

For this I guess U will have to Join the Knewton Classsroom Course

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Adam@Knewton: GMAT Instructor; Posts: 132; Joined: Mon Jan 10, 2011 12:26 pmFollowed by: 37 members; Location: New York City; Thanked: 68 times; GMAT Score:780

by Adam@Knewton » Tue Jan 18, 2011 2:02 pm

mundasingh123 wrote:
ahnan wrote:AdamKnewton, can u tell us your method to deal with this type of question?
For this I guess U will have to Join the Knewton Classsroom Course

Lol@mundasingh. I will explain how I approached it, but of course anyone is always welcome to take my Knewton Classroom Course

@ahnan:

I like to start by figuring out any big Inferences, which will likely not be the right answer but might help -- here, simply that there are more marine species facing extinction that we thought, and the author believes this as fact. However, the only real way to handle Inference questions is with confident elimination of answer choices:

A) The West Indies is mentioned in the passage, but not in relation to how many species are endangered there; this is the part where the author is introducing "other factors." Distortion. Eliminate.
B) Systematic sampling is mentioned in that it would improve our estimates of marine extinction. Yet we're not explicitly told that this technique is used for non-marine life. Therefore it seems like a Distortion again. I will keep it because it's possible I've misread it and if nothing else works I have to read it more carefully, but I think it's wrong.
C) The word "likely" is very tempting because it makes this choice not so definite and therefore more likely inferrable. As explained above, it is inferrable. Probably the answer.
D) As soon as I say "more severe than," I think it could be an Irrelevant Comparison. What's being compared? West Indies threat to Elsewhere threat. No evidence for this in the passage. Eliminate.
E) Climate change is just one of a few factors mentioned. Also, extreme language of "far below" is not mentioned in the passage. Extreme on both accounts. Eliminate.

Since (C) is so good, no reason to reread (B); I'm confident now it's a Distortion. C, final answer.

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tailoc: Junior | Next Rank: 30 Posts; Posts: 17; Joined: Wed Jun 15, 2011 11:38 am; Thanked: 1 times

by tailoc » Fri Sep 09, 2011 1:53 am

I think that in order to answer this question. We should understand method of reasoning in stimulus.
Initially, author mentioned that researchers concluded "few" of extinction. After that author used a contradiction "however". Finally, author used some details to show that extinction can high if there are some valid samplings.

Therefore, I think that author want to mention researchers' conclusion.
=> C is best answer for question.
Correct me if I have mistakes. Thank alots

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