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# Citing the frequency with which gum disease and heart

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Citing the frequency with which gum disease and heart [#permalink]

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16 Jul 2012, 11:24
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Citing the frequency with which gum disease and heart disease occur in the same patients, many dentists believe that periodontal disease is a cause of a variety of cardiovascular problems, including Coronary Artery Disease.

Which of the following, if true, would most weaken the claim that periodontal disease is a cause of Coronary Artery disease?

A. Bacteria present in infected gums can become mobile and enter the bloodstream, causing arterial plaque to accumulate.
B. People who brush and floss their teeth regularly are also more likely to exercise and eat a healthy diet.
C. Infected gums are more prone to bleeding, which allows bacteria to escape the mouth and irritate arteries.
D. People who experience loss of teeth due to periodontal disease usually cut back on many foods that are harder to chew, such as lean meats and vegetables, and increase their consumption of processed foods like pudding and ice cream.
E. Patients with no history of heart disease are much less likely to have periodontal disease than patients who have had a cardiac transplant.

Another strange question... Is it just me or do you guys also think these questions are not true representation of actual GMAT style questions..
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Re: Citing the frequency with which gum disease and heart [#permalink]

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21 Mar 2013, 11:15
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agdimple333 wrote:
Citing the frequency with which gum disease and heart disease occur in the same patients, many dentists believe that periodontal disease is a cause of a variety of cardiovascular problems, including Coronary Artery Disease.

Which of the following, if true, would most weaken the claim that periodontal disease is a cause of Coronary Artery disease?
A. Bacteria present in infected gums can become mobile and enter the bloodstream, causing arterial plaque to accumulate.
B. People who brush and floss their teeth regularly are also more likely to exercise and eat a healthy diet.
C. Infected gums are more prone to bleeding, which allows bacteria to escape the mouth and irritate arteries.
D. People who experience loss of teeth due to periodontal disease usually cut back on many foods that are harder to chew, such as lean meats and vegetables, and increase their consumption of processed foods like pudding and ice cream.
E. Patients with no history of heart disease are much less likely to have periodontal disease than patients who have had a cardiac transplant.

Another strange question... Is it just me or do you guys also think these questions are not true representation of actual GMAT style questions..

fameatop wrote:
I am not able to understand why option B is correct & E is incorrect. Can you kindly throw some light on the same. Waiting eagerly for your detailed explanation.

So far as I can tell, this is a Knewton question, and the OA is (B). First, as to agdimple333's point, while this prompt is perhaps a little on the short side, I would say the logic of the question very much captures the kind of logic you will see on GMAT CR questions. This is, in essence, a very good question --- not least because it has a very clear and well-defined OA, and yet, many folks on this page have fallen for one of the trap answers, most notably, (E).

The big underlying idea of this question is ---- correlation does not imply causality. This blog
http://magoosh.com/gmat/2012/gmat-integ ... tterplots/
is primarily about regression and correlation, but it does touch on this issue.

Let's say
P = periodontal disease
Q = cardiovascular problems
The dentists' argument is, essentially, P & Q are correlated, so P cause Q. The dentists' argument is abysmally bad, a classic flawed argument pattern.

To strengthen such an argument, we would have to demonstrate there was some mechanism of connection ---- e.g. bacteria or viruses in the mouth that become blood-borne and infect the heart, something like that.

One of the best ways to weaken a correlation/causality argument is to show that both terms arise from something else. This is in essence what (B) does. (B) says: there are a category of people --- call them "health all over" people --- and these folks take care of themselves from head to foot --- they brush and floss, which prevents periodontal disease, and separately, they eat healthy and exercise, so they don't get heart disease. That implies there would be other people, the "don't take care of self" people, who don't brush, don't floss, don't eat health, don't exercise, don't laugh, don't sing, don't do much of anything to take care of themselves. These latter people would be prime candidates to get periodontal disease (from not brushing & flossing) as well as heart disease (from poor diet and no exercise), but the periodontal disease and the heart disease do not have relationship of causality with one another --- rather, they are both products of an overall unhealthy lifestyle. This decisively weakens the argument, which is all about the leap from correlation to causality.

By contrast, (E) simply provides more evidence for the correlation. We already know P & Q are correlated. That was the first sentence. That's the evidence in this argument. That's beyond doubt. The crux of the argument is this vast logical leap from correlation to causality. Choice (E) simply gives more evidence that P & Q are correlated. In a strange way, it is a kind of strengthener, insofar as it reinforces evidence. It doesn't address the issue of causality and it doesn't clearly weaken the argument.
Another way to weaken the argument "P causes Q" would be to show that, actually, Q causes P --- something along those lines would be a good weakener, but (E) doesn't clearly support this.

Does all this make sense?

Mike
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Re: Citing the frequency with which gum disease and heart [#permalink]

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22 Mar 2013, 20:26
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agdimple333 wrote:
Citing the frequency with which gum disease and heart disease occur in the same patients, many dentists believe that periodontal disease is a cause of a variety of cardiovascular problems, including Coronary Artery Disease.

Which of the following, if true, would most weaken the claim that periodontal disease is a cause of Coronary Artery disease?

A. Bacteria present in infected gums can become mobile and enter the bloodstream, causing arterial plaque to accumulate.
B. People who brush and floss their teeth regularly are also more likely to exercise and eat a healthy diet.
C. Infected gums are more prone to bleeding, which allows bacteria to escape the mouth and irritate arteries.
D. People who experience loss of teeth due to periodontal disease usually cut back on many foods that are harder to chew, such as lean meats and vegetables, and increase their consumption of processed foods like pudding and ice cream.
E. Patients with no history of heart disease are much less likely to have periodontal disease than patients who have had a cardiac transplant.

Another strange question... Is it just me or do you guys also think these questions are not true representation of actual GMAT style questions..

Responding to a pm:

Two issues, gum problems and heart problems, often appear together - but it doesn't imply a causal relation between them. There could be a common underlying cause which makes them appear together.
Option B gives you that common cause - lifestyle.

People with unhealthy lifestyles tend to suffer from both the problems since they don't brush and they don't exercise and eat healthy.
People who ignored B because 'A implies B' doesn't mean 'Not A implies Not B' - very good. But, there is a catch here. It is not the simple logical relation 'A implies B' in option (B). Option (B) says that 'people who brush are also more likely to exercise' Notice the words 'more likely'. It gives you a comparison. So logically, people who brush are more likely to exercise as compared to people who don't brush. So people who don't brush are less likely to exercise and hence the lifestyle issue we talked about.

Let me discuss (C), (D) and (E)

C. Infected gums are more prone to bleeding, which allows bacteria to escape the mouth and irritate arteries.
If this is true, gum problems might actually cause heart problems. Infected gums lead to irritated arteries. This is a strengthener.

D. People who experience loss of teeth due to periodontal disease usually cut back on many foods that are harder to chew, such as lean meats and vegetables, and increase their consumption of processed foods like pudding and ice cream.
I am actually in two minds about this option. The way it is worded, it makes you feel that people have a choice - they choose to cut back on harder (but healthier) foods and consume more processed foods. It that is the case, then gum problems do not cause heart problems; instead, it's people's choices (read processed food) that cause that cause heart problems.
This option should have been worded a little differently e.g.
'People who experience loss of teeth due to periodontal disease NEED to cut back on many foods that are harder to chew, such as lean meats and vegetables, and increase their consumption of processed foods, which have a softer texture.'
Basically, something that tells us that it is not a choice they make. They are forced to do it due to gum problems which means gum problems indirectly cause heart problems. Just like in option (A), people cannot help it if bacteria from their gums enter the bloodstream and cause heart problems, similarly, if they are forced to change their eating pattern due to problems, then we can say that gum problems cause heart problems.

E. Patients with no history of heart disease are much less likely to have periodontal disease than patients who have had a cardiac transplant.
What does this option tell you? Basically, it just tells you that gum diseases and heart diseases often appear together. It doesn't say anything about heart disease being the cause of gum disease. Our premises in the argument are from the perspective of a gum disease patient (say, if we studied people with gum diseases). This option is from the perspective of heart disease patients (if instead we surveyed the heart disease patients). The conclusion drawn is the same in both - gum diseases and heart diseases are often found together. So actually, it adds no new info.
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16 Jul 2012, 11:56
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With this kind of the argument:

A and B happen in the same patient, then A => B.

How to weaken this conclusion. choice (D) states that, due to A ( periodontal disease), the eating habits of patients change, making the cause to the disease B ( cardiovascular disease).

Choice (E) is the reverse choice, strengthen the argument by assert that B not cause A. The 3 remain first answers are easy to spot, so I did not mention in my reasoning.
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17 Jul 2012, 19:30
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I would go with E because it clearly says if there is a dental disease it leads to heart disease. All other options prove that dental does leads to heart disease.

Its only E that says that its not necessary that they are related
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Re: Citing the frequency with which gum disease and heart [#permalink]

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22 Mar 2013, 11:44
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I cannot believe option B weakens the conclusion. No dental problems - healthy food - no heart problems. This absolutely reinforces the conclusion and nobody can make me think otherwise

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This is why people should only use official questions.
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Re: Citing the frequency with which gum disease and heart [#permalink]

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08 Oct 2013, 05:44
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mikemcgarry wrote:
agdimple333 wrote:
Citing the frequency with which gum disease and heart disease occur in the same patients, many dentists believe that periodontal disease is a cause of a variety of cardiovascular problems, including Coronary Artery Disease.

Which of the following, if true, would most weaken the claim that periodontal disease is a cause of Coronary Artery disease?
A. Bacteria present in infected gums can become mobile and enter the bloodstream, causing arterial plaque to accumulate.
B. People who brush and floss their teeth regularly are also more likely to exercise and eat a healthy diet.
C. Infected gums are more prone to bleeding, which allows bacteria to escape the mouth and irritate arteries.
D. People who experience loss of teeth due to periodontal disease usually cut back on many foods that are harder to chew, such as lean meats and vegetables, and increase their consumption of processed foods like pudding and ice cream.
E. Patients with no history of heart disease are much less likely to have periodontal disease than patients who have had a cardiac transplant.

Another strange question... Is it just me or do you guys also think these questions are not true representation of actual GMAT style questions..

fameatop wrote:
I am not able to understand why option B is correct & E is incorrect. Can you kindly throw some light on the same. Waiting eagerly for your detailed explanation.

So far as I can tell, this is a Knewton question, and the OA is (B). First, as to agdimple333's point, while this prompt is perhaps a little on the short side, I would say the logic of the question very much captures the kind of logic you will see on GMAT CR questions. This is, in essence, a very good question --- not least because it has a very clear and well-defined OA, and yet, many folks on this page have fallen for one of the trap answers, most notably, (E).

The big underlying idea of this question is ---- correlation does not imply causality. This blog
is primarily about regression and correlation, but it does touch on this issue.

Let's say
P = periodontal disease
Q = cardiovascular problems
The dentists' argument is, essentially, P & Q are correlated, so P cause Q. The dentists' argument is abysmally bad, a classic flawed argument pattern.

To strengthen such an argument, we would have to demonstrate there was some mechanism of connection ---- e.g. bacteria or viruses in the mouth that become blood-borne and infect the heart, something like that.

One of the best ways to weaken a correlation/causality argument is to show that both terms arise from something else. This is in essence what (B) does. (B) says: there are a category of people --- call them "health all over" people --- and these folks take care of themselves from head to foot --- they brush and floss, which prevents periodontal disease, and separately, they eat healthy and exercise, so they don't get heart disease. That implies there would be other people, the "don't take care of self" people, who don't brush, don't floss, don't eat health, don't exercise, don't laugh, don't sing, don't do much of anything to take care of themselves. These latter people would be prime candidates to get periodontal disease (from not brushing & flossing) as well as heart disease (from poor diet and no exercise), but the periodontal disease and the heart disease do not have relationship of causality with one another --- rather, they are both products of an overall unhealthy lifestyle. This decisively weakens the argument, which is all about the leap from correlation to causality.

By contrast, (E) simply provides more evidence for the correlation. We already know P & Q are correlated. That was the first sentence. That's the evidence in this argument. That's beyond doubt. The crux of the argument is this vast logical leap from correlation to causality. Choice (E) simply gives more evidence that P & Q are correlated. In a strange way, it is a kind of strengthener, insofar as it reinforces evidence. It doesn't address the issue of causality and it doesn't clearly weaken the argument.
Another way to weaken the argument "P causes Q" would be to show that, actually, Q causes P --- something along those lines would be a good weakener, but (E) doesn't clearly support this.

Does all this make sense?

Mike

Thanks Mike, this explanation was clear. But reading it gave me the impression that the question is not representative of what Official GMAT would look like. GMAT answers wouldn't require any sort of "over" inference, but answering B was necessary to infer something beyond, as you've pointed out:

"they eat healthy and exercise, so they don't get heart disease."

In other words, to choose answer B is necessary to assume that healthy habits and exercise prevent someone from getting the heart disease (real world true, but the question really implied that?). This is what refrained me from picking B.
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16 Jul 2012, 12:04
IMO,

Premise;

dental ailment----->cardiac diseases

B. People who brush and floss their teeth regularly are also more likely to exercise and eat a healthy diet

no dental diseases----->no cardiac diseases

weakens the argument by negating it
( Negation is not used here to find assumption by hitting the argument to see its consequences rather, negation is used to just weaken the argument)

(B) wins.
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16 Jul 2012, 12:11
Either Bacterial gum or infected gum(other than bacterial) is the subject of periodontics?
else all the ACs are looking similar to us.
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16 Jul 2012, 19:25
thevenus wrote:
IMO,

Premise;

dental ailment----->cardiac diseases

B. People who brush and floss their teeth regularly are also more likely to exercise and eat a healthy diet

no dental diseases----->no cardiac diseases

weakens the argument by negating it
( Negation is not used here to find assumption by hitting the argument to see its consequences rather, negation is used to just weaken the argument)

(B) wins.

The conclusion of the argument = dental disease (A) cause cardiovascular disease (B)

Weaken the conclusion cannot be NOT (A) => NOT (B)
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16 Jul 2012, 21:45
I would say E.

A- Ruled out.Reinforces the conclusion.
B- Ruled out.Reinforces the conclusion. (No dental problem-> No cardio problem)
C- Ruled out.Reinforces the conclusion.
D- Ruled out.Reinforces the conclusion. (Denatl problem-> intake of processed food.Processed food is in a way irrelevant- we cannot conclude anything as per the given question - and even if we say that processed food causes cardio problems, it can be ruled out as it reinforces the conclusion.)
E - Correct. No cardio problem-> may or may not have dental problem. This means that even if someone has a dental problem, they may not have a cardio problem.
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17 Jul 2012, 03:07
I think the answer should be D.

B. People who brush and floss their teeth regularly are also more likely to exercise and eat a healthy diet. - People who brush and floss their teeth regularly also exercise and eat healthy diet. But it doesn't mean that they don't suffer from periodontal disease.
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17 Jul 2012, 07:30
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17 Jul 2012, 14:21
Citing the frequency with which gum disease and heart disease occur in the same patients, many dentists believe that periodontal disease is a cause of a variety of cardiovascular problems, including Coronary Artery Disease.

Which of the following, if true, would most weaken the claim that periodontal disease is a cause of Coronary Artery disease?

A. Bacteria present in infected gums can become mobile and enter the bloodstream, causing arterial plaque to accumulate.
B. People who brush and floss their teeth regularly are also more likely to exercise and eat a healthy diet.
C. Infected gums are more prone to bleeding, which allows bacteria to escape the mouth and irritate arteries.
D. People who experience loss of teeth due to periodontal disease usually cut back on many foods that are harder to chew, such as lean meats and vegetables, and increase their consumption of processed foods like pudding and ice cream.
E. Patients with no history of heart disease are much less likely to have periodontal disease than patients who have had a cardiac transplant.

---

premise : fequency with which gum disease and heart disease occur in the same patients

conclusion : any dentists believe that periodontal disease is a cause of a variety of cardiovascular problems, including Coronary Artery Disease.

we can weaken this argument by following ways.

a. challenging the information
b. showing that cause occurs but effect does not occur
c. showing that effect occurs but cause does not occur...
--------
A. Bacteria present in infected gums can become mobile and enter the bloodstream, causing arterial plaque to accumulate. (Not Related to conclusion).. Therefore putting a BLANK
B. People who brush and floss their teeth regularly are also more likely to exercise and eat a healthy diet. (Not Related to conclusion).. Therefore putting a BLANK
C. Infected gums are more prone to bleeding, which allows bacteria to escape the mouth and irritate arteries. W This can be a weakener as it says that arteries could be impacted to another cause which is infected gums
D. People who experience loss of teeth due to periodontal disease usually cut back on many foods that are harder to chew, such as lean meats and vegetables, and increase their consumption of processed foods like pudding and ice cream. now this answer is half correct and half wrong.. it does not mention the periodontal disease but it does not conclude the non existence of heart disease.
E. Patients with no history of heart disease are much less likely to have periodontal disease than patients who have had a cardiac transplant. to me this is strengthening the argument. (S)

Hence my answer would be "C"
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19 Jul 2012, 06:09
To me it seems E and I think it's the strongest option
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19 Jul 2012, 06:40
B looks good.

This indicates that there is no relation between coronary artery disease and gum disease.

E:

It restates the evidence from the prompt: periodontal disease and cardiovascular problems often occur in the same patients. There's no indication here which would be cause and which would be effect.
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Re: Citing the frequency with which gum disease and heart [#permalink]

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21 Mar 2013, 20:11
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Hi Mike,
If the option E states
Patients with no history of heart disease do not suffer from periodontal disease. - Would this weaken the argument. As per me it should weaken.

Original option E
E. Patients with no history of heart disease are much less likely to have periodontal disease than patients who have had a cardiac transplant.

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Re: Citing the frequency with which gum disease and heart [#permalink]

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22 Mar 2013, 10:39
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fameatop wrote:
Hi Mike,
If the option E states
Patients with no history of heart disease do not suffer from periodontal disease. - Would this weaken the argument. As per me it should weaken.

Original option E
E. Patients with no history of heart disease are much less likely to have periodontal disease than patients who have had a cardiac transplant.

Both versions, the original (E) and your modified (E), are strengtheners, insofar as they reinforce the evidence. They don't really provide additional support, but they are entirely consistent with a scenario in which the argument is true.

Pretend for a moment, that the dentists are 100% correct. Let's make it even more extreme -- pretend that periodontal disease is the only cause of heart disease. This is a hyper-strengthened version of the argument. In this version, it would most certain be the case that "Patients with no history of heart disease do not suffer from periodontal disease", because as soon as someone got the least little plaque on their teeth, they would go down with a coronary. Periodontal disease and heart disease would go together 100% of the time, so you would never find one without the other. That is what would be true in an over-the-top strengthened version of the argument. Anything consistent with this scenario is most certainly not a weakener.

Does that make sense?

Mike
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Re: Citing the frequency with which gum disease and heart [#permalink]

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23 Mar 2013, 03:34
agdimple333 wrote:
Citing the frequency with which gum disease and heart disease occur in the same patients, many dentists believe that periodontal disease is a cause of a variety of cardiovascular problems, including Coronary Artery Disease.

Which of the following, if true, would most weaken the claim that periodontal disease is a cause of Coronary Artery disease?

A. Bacteria present in infected gums can become mobile and enter the bloodstream, causing arterial plaque to accumulate.
B. People who brush and floss their teeth regularly are also more likely to exercise and eat a healthy diet.
C. Infected gums are more prone to bleeding, which allows bacteria to escape the mouth and irritate arteries.
D. People who experience loss of teeth due to periodontal disease usually cut back on many foods that are harder to chew, such as lean meats and vegetables, and increase their consumption of processed foods like pudding and ice cream.
E. Patients with no history of heart disease are much less likely to have periodontal disease than patients who have had a cardiac transplant.

Another strange question... Is it just me or do you guys also think these questions are not true representation of actual GMAT style questions..

Premise: Erequency with which gum disease and heart disease occur in the same patients is high

Conclusion: Gum disease is a cause of a variety of cardiovascular problems, including Coronary Artery Disease.

Since this is a weaken question, we need to find the choice that,

(i) weakens the premise or,
(ii) weakens the conclusion

To do (i) the choice needs to show that the frequency of gum disease and heart disease occurring in the same patients is not high. If for some reason a choice shows that this is really the case, then the premise will be weakened.

To do (ii) the choice has to show that gum disease may not be the cause of heart problems. That is how the conclusion is weakened.

Choice B does (ii) because it suggests that those who do not take care of their teeth are those who are likely to have unhealthy food habits and that indeed is the cause of their heart problems .

Other choices do neither (i) nor (ii).

Hence the answer is choice B.
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Re: Citing the frequency with which gum disease and heart [#permalink]

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09 Sep 2013, 03:51
mikemcgarry wrote:
agdimple333 wrote:
Citing the frequency with which gum disease and heart disease occur in the same patients, many dentists believe that periodontal disease is a cause of a variety of cardiovascular problems, including Coronary Artery Disease.

Which of the following, if true, would most weaken the claim that periodontal disease is a cause of Coronary Artery disease?
A. Bacteria present in infected gums can become mobile and enter the bloodstream, causing arterial plaque to accumulate.
B. People who brush and floss their teeth regularly are also more likely to exercise and eat a healthy diet.
C. Infected gums are more prone to bleeding, which allows bacteria to escape the mouth and irritate arteries.
D. People who experience loss of teeth due to periodontal disease usually cut back on many foods that are harder to chew, such as lean meats and vegetables, and increase their consumption of processed foods like pudding and ice cream.
E. Patients with no history of heart disease are much less likely to have periodontal disease than patients who have had a cardiac transplant.

Another strange question... Is it just me or do you guys also think these questions are not true representation of actual GMAT style questions..

fameatop wrote:
I am not able to understand why option B is correct & E is incorrect. Can you kindly throw some light on the same. Waiting eagerly for your detailed explanation.

So far as I can tell, this is a Knewton question, and the OA is (B). First, as to agdimple333's point, while this prompt is perhaps a little on the short side, I would say the logic of the question very much captures the kind of logic you will see on GMAT CR questions. This is, in essence, a very good question --- not least because it has a very clear and well-defined OA, and yet, many folks on this page have fallen for one of the trap answers, most notably, (E).

The big underlying idea of this question is ---- correlation does not imply causality. This blog
http://magoosh.com/gmat/2012/gmat-integ ... tterplots/
is primarily about regression and correlation, but it does touch on this issue.

Let's say
P = periodontal disease
Q = cardiovascular problems
The dentists' argument is, essentially, P & Q are correlated, so P cause Q. The dentists' argument is abysmally bad, a classic flawed argument pattern.

To strengthen such an argument, we would have to demonstrate there was some mechanism of connection ---- e.g. bacteria or viruses in the mouth that become blood-borne and infect the heart, something like that.

One of the best ways to weaken a correlation/causality argument is to show that both terms arise from something else. This is in essence what (B) does. (B) says: there are a category of people --- call them "health all over" people --- and these folks take care of themselves from head to foot --- they brush and floss, which prevents periodontal disease, and separately, they eat healthy and exercise, so they don't get heart disease. That implies there would be other people, the "don't take care of self" people, who don't brush, don't floss, don't eat health, don't exercise, don't laugh, don't sing, don't do much of anything to take care of themselves. These latter people would be prime candidates to get periodontal disease (from not brushing & flossing) as well as heart disease (from poor diet and no exercise), but the periodontal disease and the heart disease do not have relationship of causality with one another --- rather, they are both products of an overall unhealthy lifestyle. This decisively weakens the argument, which is all about the leap from correlation to causality.

By contrast, (E) simply provides more evidence for the correlation. We already know P & Q are correlated. That was the first sentence. That's the evidence in this argument. That's beyond doubt. The crux of the argument is this vast logical leap from correlation to causality. Choice (E) simply gives more evidence that P & Q are correlated. In a strange way, it is a kind of strengthener, insofar as it reinforces evidence. It doesn't address the issue of causality and it doesn't clearly weaken the argument.
Another way to weaken the argument "P causes Q" would be to show that, actually, Q causes P --- something along those lines would be a good weakener, but (E) doesn't clearly support this.

Does all this make sense?

Mike

Dear Mike
If option E were to be a weakener then, what would that option be?
As you said, (P causes Q) weakener would be (Q causes P). is this the classic weakener to use on these question types?
Re: Citing the frequency with which gum disease and heart   [#permalink] 09 Sep 2013, 03:51

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