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# A recent survey of all auto accident victims in Dole County found that

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A recent survey of all auto accident victims in Dole County found that  [#permalink]

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30 Mar 2009, 01:38
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35% (01:58) correct 65% (02:04) wrong based on 1269 sessions

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A recent survey of all auto accident victims in Dole County found that, of the severely injured drivers and front-seat passengers, 80 percent were not wearing seat belts at the time of their accidents. This indicates that, by wearing seat belts, drivers and front-seat passengers can greatly reduce their risk of being severely injured if they are in an auto accident.

The conclusion above is not properly drawn unless which of the following is true?

(A) Of all the drivers and front-seat passengers in the survey, more than 20 percent were wearing seat belts at the time of their accidents.

(B) Considerably more than 20 percent of drivers and front-seat passengers in Dole County always wear seat belts when traveling by car.

(C) More drivers and front-seat passengers in the survey than rear-seat passengers were very severely injured.

(D) More than half of the drivers and front-seat passengers in the survey were not wearing seat belts at the time of their accidents.

(E) Most of the auto accidents reported to police in Dole County do not involve any serious injury.
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Re: A recent survey of all auto accident victims in Dole County found that  [#permalink]

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26 Mar 2011, 00:14
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This argument comes to a conclusion about the benefits of seatbelts without providing any data about what happens to people who wear them. Let's look at a similar scenario: Imagine that I perform a study that finds that most people with heart disease are not Dutch. Could I conclude that being Dutch protects against heart disease? No, because most people *without* heart disease aren't Dutch, either! I would have to see some data showing that Dutch people show up more in the general population than they do among heart disease sufferers.

Similarly, if we look at all the people who get in accidents--whether they get injured or not--and we don't see more than 20% wearing their seatbelts, then this data doesn't show that seatbelts are safe. It just shows that not many people wear them. If that's the case, then the conclusion doesn't make much sense--seatbelt wearers appear to be getting injured just as much as everyone else (even more, if they represent *less* than 20% of the group). On the other hand, if the assumption in A is correct, and more than 20% of people who get in accidents have their seatbelts on, then we have to wonder why more of them weren't injured. The conclusion starts to look much better.

I hope that helps!
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Re: A recent survey of all auto accident victims in Dole County found that  [#permalink]

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05 Apr 2009, 10:03
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A recent survey of all auto accident victims in Dole County found that, of the severely injured drivers and front-seat passengers, 80 percent were not wearing seat belts at the time of their accidents. This indicates that, by wearing seat belts, drivers and front-seat passengers can greatly reduce their risk of being severely injured if they are in an auto accident.

The conclusion above is not properly drawn unless which of the following is true?

Explanation:
--------------------
(A) Of all the drivers and front-seat passengers in the survey, more than 20 percent were wearing seat belts at the time of their accidents. ---> We know from the excerpt that
Drivers + Front-Seat Passengers = Severely Injured (20% Wearing Seat-Belts + 80% Not Wearing Seat-Belts) + Not Severely Injured (No Information)

Now, what if more than 80% of the drivers and front-seat passengers who were NOT severely injured were NOT wearing seat-belts? Using this scenario, we can say that wearing seat-belts will NOT reduce the risk of being severely injured. So the conclusion cannot be properly drawn.

Since we have to show that author's conclusion was properly drawn, we have to show that the scenario I cited above was not possible. To make the above scenario impossible, we can say that more than 80% (actually it should be 100% otherwise these people will come under the category of ‘severely injured’ ones) of the drivers and front-seat passengers who were NOT severely injured were wearing seat-belts. Also, excerpt mentions that 20% people from the severely injured category were wearing seat-belts.

So, if we add people (who were wearing seat-belts) from both the categories (severely injured & not severely injured), we'll arrive at the assumption stated in this option.

(B) Considerably more than 20 percent of drivers and front-seat passengers in Dole County always wear seat belts when traveling by car. ---> Mentions about car. Irrelevant.

(C) More drivers and front-seat passengers in the survey than rear-seat passengers were very severely injured. ---> Will not help us in any way to prove that the conclusion was properly drawn.

(D) More than half of the drivers and front-seat passengers in the survey were not wearing seat belts at the time of their accidents. ---> This cannot be the assumption in order to arrive at the author’s conclusion.

(E) Most of the auto accidents reported to police in Dole County do not involve any serious injury. ---> Irrelevant.
--------------------

Hope that helps.

Regards,
Technext
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Re: A recent survey of all auto accident victims in Dole County found that  [#permalink]

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30 Mar 2009, 11:55
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IMO A. I was confused between A and D but finally opted A.

ritula wrote:
A recent survey of all auto accident victims in Dole County found that, of the severely injured drivers and front-seat passengers, 80 percent were not wearing seat belts at the time of their accidents. This indicates that, by wearing seat belts, drivers and front-seat passengers can greatly reduce their risk of being severely injured if they are in an auto accident.

The conclusion above is not properly drawn unless which of the following is true?

(A) Of all the drivers and front-seat passengers in the survey, more than 20 percent were wearing seat belts at the time of their accidents.
(B) Considerably more than 20 percent of drivers and front-seat passengers in Dole County always wear seat belts when traveling by car.
-- OOS
(C) More drivers and front-seat passengers in the survey than rear-seat passengers were very severely injured.
-- OOS
(D) More than half of the drivers and front-seat passengers in the survey were not wearing seat belts at the time of their accidents.
(E) Most of the auto accidents reported to police in Dole County do not involve any serious injury.
-- OOS

We have to find out why argument believes "wearing seat belts, ... can greatly reduce . risk"? Of course some proof is required to stand this point.
A) see the blue part: were wearing - this does validate the claim
D) were not wearing - this does not validate the claim [extra line of assumption is precarious on GMAT]
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Re: A recent survey of all auto accident victims in Dole County found that  [#permalink]

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30 Mar 2009, 16:11
1
Premise: A recent survey of all auto accident victims in Dole County found that, of the severely injured drivers and front-seat passengers, 80 percent were not wearing seat belts at the time of their accidents

Conclusion: By wearing seat belts, drivers and front-seat passengers can greatly reduce their risk of being severely injured if they are in an auto accident.

Answer is asking for an additional premise to strengthen the conclusion:

(A) Of all the drivers and front-seat passengers in the survey, more than 20 percent were wearing seat belts at the time of their accidents. - Perfect. Of all the people in the survey 80% of those injured didn't wear seat belts, 20% wore seat belts - which strengthens the conclusion
(B) Considerably more than 20 percent of drivers and front-seat passengers in Dole County always wear seat belts when traveling by car. - Always has no relevance, the argument talks about accidental impact.
(C) More drivers and front-seat passengers in the survey than rear-seat passengers were very severely injured. - Doesn't add anything to strengthen the conclusion
(D) More than half of the drivers and front-seat passengers in the survey were not wearing seat belts at the time of their accidents. Nothing to support or strengthen the conclusion
(E) Most of the auto accidents reported to police in Dole County do not involve any serious injury.
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Re: A recent survey of all auto accident victims in Dole County found that  [#permalink]

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30 Mar 2009, 19:13
3
ritula wrote:
A recent survey of all auto accident victims in Dole County found that, of the severely injured drivers and front-seat passengers, 80 percent were not wearing seat belts at the time of their accidents. This indicates that, by wearing seat belts, drivers and front-seat passengers can greatly reduce their risk of being severely injured if they are in an auto accident.

The conclusion above is not properly drawn unless which of the following is true?

(A) Of all the drivers and front-seat passengers in the survey, more than 20 percent were wearing seat belts at the time of their accidents.

If 80% are NOT wearing SB, How can more than 20% wear SB? Wrong.

(B) Considerably more than 20 percent of drivers and front-seat passengers in Dole County always wear seat belts when traveling by car.

Expands scope to all drivers. Wrong

(C) More drivers and front-seat passengers in the survey than rear-seat passengers were very severely injured.

Premise gives a statistic and conclusion makes a judgment on how severity of injuries can be reduced. So seems to connect them.

(D) More than half of the drivers and front-seat passengers in the survey were not wearing seat belts at the time of their accidents.

Isnt this a restatement or possibly contradiction of the premise. more than 50% means could be <=80% or more than 80%

(E) Most of the auto accidents reported to police in Dole County do not involve any serious injury.

If they dont involve any serious injury at all, belts do not help any thing.

Assumption Q based on connect the premise and conclusion or fill the logical gap.
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Re: A recent survey of all auto accident victims in Dole County found that  [#permalink]

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02 Sep 2009, 06:41
3
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A is correct.
Lets say there were 100 cases of "serious" accident. Then 80 of those cases were not wearing seat-belts according to the author. But 20 were. So the author assumes that wearing seat-belts can prevent serious accidents. How can that be? There are 20 cases of serious accident that were wearing seat belts! Then how can the author claim that seat-belts can prevent serious accidents? The only way this can happen is if more than 20 people in the auto-accident survey were wearing seat belts and were not seriously hurt. Choice A provides us with that number- it says more than 20% of ALL accident cases were wearing seat-belts at the time of the accident. Now 20% of ALL cases has to be > 20% of serious cases since "serious cases" is a sub-group of all cases.
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Re: A recent survey of all auto accident victims in Dole County found that  [#permalink]

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07 Sep 2012, 14:14
i will go with C.

(A) Of all the drivers and front-seat passengers in the survey, more than 20 percent were wearing seat belts at the time of their accidents.-It contradicts the premise it cannot be more than 20% since 80% people in survey were not wearing
(B)Considerably more than 20 percent of drivers and front-seat passengers in Dole County always wear seat belts when traveling by car.---This doesnot tell us anything,maybe 40% even wore we are talking about people in survey.
(C) More drivers and front-seat passengers in the survey than rear-seat passengers were very severely injured.
--by wearing seat belts, drivers and front-seat passengers can greatly reduce their risk of being severely injured
This seems to connect the dots, if front seat passengers are seriously injured then seatbelt will surely help them.
(D) More than half of the drivers and front-seat passengers in the survey were not wearing seat belts at the time of their accidents.-grbgrgrbgrbgr again similar to B
(E) Most of the auto accidents reported to police in Dole County do not involve any serious injury.
o yea same thing happens in my county also
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Re: A recent survey of all auto accident victims in Dole County found that  [#permalink]

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07 Sep 2012, 21:44
1
jitgoel wrote:
A recent survey of all auto accident victims in Dole County found that, of the severely injured drivers and front-seat passengers, 80 percent were not wearing seat belts at the time of their accidents. This indicates that, by wearing seat belts, drivers and front-seat passengers can greatly reduce their risk of being severely injured if they are in an auto accident.
The conclusion above is not properly drawn unless which of the following is true?
(A) Of all the drivers and front-seat passengers in the survey, more than 20 percent were wearing seat belts at the time of their accidents.
(B)Considerably more than 20 percent of drivers and front-seat passengers in Dole County always wear seat belts when traveling by car.
(C) More drivers and front-seat passengers in the survey than rear-seat passengers were very severely injured.
(D) More than half of the drivers and front-seat passengers in the survey were not wearing seat belts at the time of their accidents.
(E) Most of the auto accidents reported to police in Dole County do not involve any serious injury.

Hi jitgoel,

This problem gives us evidence that 80% of injuries in car accidents are from folks not wearing seat belts. The argument's conclusion is that seat belts work. So, what's missing here? Well, we have no context about the 80%; it sounds scarily high, but we don't actually know that! The authors' assumption is that 80% of injuries makes up a disproportionate number of injuries to non-wearers. After all, if 80% of people don't wear seat belts, it's little surprise they suffered 80% of accidents! (B) tells us that this is not the case; the author's assumption that 80% is significant is in fact correct, and therefore so is his conclusion. (B) is the answer.
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Prepare with Kaplan and save $150 on a course! Kaplan Reviews Manager Joined: 23 Aug 2011 Posts: 75 Re: A recent survey of all auto accident victims in Dole County found that [#permalink] ### Show Tags 08 Sep 2012, 00:23 KapTeacherEli wrote: jitgoel wrote: A recent survey of all auto accident victims in Dole County found that, of the severely injured drivers and front-seat passengers, 80 percent were not wearing seat belts at the time of their accidents. This indicates that, by wearing seat belts, drivers and front-seat passengers can greatly reduce their risk of being severely injured if they are in an auto accident. The conclusion above is not properly drawn unless which of the following is true? (A) Of all the drivers and front-seat passengers in the survey, more than 20 percent were wearing seat belts at the time of their accidents. (B)Considerably more than 20 percent of drivers and front-seat passengers in Dole County always wear seat belts when traveling by car. (C) More drivers and front-seat passengers in the survey than rear-seat passengers were very severely injured. (D) More than half of the drivers and front-seat passengers in the survey were not wearing seat belts at the time of their accidents. (E) Most of the auto accidents reported to police in Dole County do not involve any serious injury. Hi jitgoel, This problem gives us evidence that 80% of injuries in car accidents are from folks not wearing seat belts. The argument's conclusion is that seat belts work. So, what's missing here? Well, we have no context about the 80%; it sounds scarily high, but we don't actually know that! The authors' assumption is that 80% of injuries makes up a disproportionate number of injuries to non-wearers. After all, if 80% of people don't wear seat belts, it's little surprise they suffered 80% of accidents! (B) tells us that this is not the case; the author's assumption that 80% is significant is in fact correct, and therefore so is his conclusion. (B) is the answer. Oops i completely missed this one. Can you let me know why C is wrong? I thought the question was asking for a premise which can strengthen the conclusion rather than an assumption. As for (B), "Considerably more than 20 percent of drivers and front-seat passengers in Dole County always wear seat belts when traveling by car." i thought this this meant some percentage range from 20% to lets say 60% folks wear seat belts, however i'm still having hard time to find out how it is necessary for the conclusion? _________________ Whatever one does in life is a repetition of what one has done several times in one's life! If my post was worth it, then i deserve kudos Kaplan GMAT Instructor Joined: 25 Aug 2009 Posts: 640 Location: Cambridge, MA Re: A recent survey of all auto accident victims in Dole County found that [#permalink] ### Show Tags 08 Sep 2012, 13:24 conty911 wrote: KapTeacherEli wrote: jitgoel wrote: A recent survey of all auto accident victims in Dole County found that, of the severely injured drivers and front-seat passengers, 80 percent were not wearing seat belts at the time of their accidents. This indicates that, by wearing seat belts, drivers and front-seat passengers can greatly reduce their risk of being severely injured if they are in an auto accident. The conclusion above is not properly drawn unless which of the following is true? (A) Of all the drivers and front-seat passengers in the survey, more than 20 percent were wearing seat belts at the time of their accidents. (B)Considerably more than 20 percent of drivers and front-seat passengers in Dole County always wear seat belts when traveling by car. (C) More drivers and front-seat passengers in the survey than rear-seat passengers were very severely injured. (D) More than half of the drivers and front-seat passengers in the survey were not wearing seat belts at the time of their accidents. (E) Most of the auto accidents reported to police in Dole County do not involve any serious injury. Hi jitgoel, This problem gives us evidence that 80% of injuries in car accidents are from folks not wearing seat belts. The argument's conclusion is that seat belts work. So, what's missing here? Well, we have no context about the 80%; it sounds scarily high, but we don't actually know that! The authors' assumption is that 80% of injuries makes up a disproportionate number of injuries to non-wearers. After all, if 80% of people don't wear seat belts, it's little surprise they suffered 80% of accidents! (B) tells us that this is not the case; the author's assumption that 80% is significant is in fact correct, and therefore so is his conclusion. (B) is the answer. Oops i completely missed this one. Can you let me know why C is wrong? I thought the question was asking for a premise which can strengthen the conclusion rather than an assumption. As for (B), "Considerably more than 20 percent of drivers and front-seat passengers in Dole County always wear seat belts when traveling by car." i thought this this meant some percentage range from 20% to lets say 60% folks wear seat belts, however i'm still having hard time to find out how it is necessary for the conclusion? (C) is irrelevant because it relies on an unstated assumption similar to the one in the main argument--without knowing the total number of front seat drivers versus the number of rear seat passengers, the number of front and rear seat injuries don't actually tell us anything. _________________ Eli Meyer Kaplan Teacher http://www.kaptest.com/GMAT Prepare with Kaplan and save$150 on a course!

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Re: A recent survey of all auto accident victims in Dole County found that  [#permalink]

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10 Sep 2012, 10:01
KapTeacherEli wrote:
jitgoel wrote:
A recent survey of all auto accident victims in Dole County found that, of the severely injured drivers and front-seat passengers, 80 percent were not wearing seat belts at the time of their accidents. This indicates that, by wearing seat belts, drivers and front-seat passengers can greatly reduce their risk of being severely injured if they are in an auto accident.
The conclusion above is not properly drawn unless which of the following is true?
(A) Of all the drivers and front-seat passengers in the survey, more than 20 percent were wearing seat belts at the time of their accidents.
(B)Considerably more than 20 percent of drivers and front-seat passengers in Dole County always wear seat belts when traveling by car.
(C) More drivers and front-seat passengers in the survey than rear-seat passengers were very severely injured.
(D) More than half of the drivers and front-seat passengers in the survey were not wearing seat belts at the time of their accidents.
(E) Most of the auto accidents reported to police in Dole County do not involve any serious injury.

Hi jitgoel,

This problem gives us evidence that 80% of injuries in car accidents are from folks not wearing seat belts. The argument's conclusion is that seat belts work. So, what's missing here? Well, we have no context about the 80%; it sounds scarily high, but we don't actually know that! The authors' assumption is that 80% of injuries makes up a disproportionate number of injuries to non-wearers. After all, if 80% of people don't wear seat belts, it's little surprise they suffered 80% of accidents! (B) tells us that this is not the case; the author's assumption that 80% is significant is in fact correct, and therefore so is his conclusion. (B) is the answer.
Whoops, looks like I missed something on this one!

(B) doesn't actually have to be true here. The reason is the word that should have made me suspicious from the get-go: "always." We need more than 20% of Dole County drivers to be wearing seatbelts, yes--but it doesn't have to be the same 20% on any given day. As long as more than 20% of the riders on the road are wearing their seatbelts, the argument is properly reasoned, so (B) is a (subtle) distortion.

(A), however, is the correct answer based on my reasoning above--which was the correct reasoning! Remember, the 80% that were injured is only a subset of those surveyed, the severely hurt group. We need to know that, among the group not severely injured, more than 20% were wearing seatbelts, which is what (A) gives us.

(C) is irrelevant as I said above--without relative numbers of front- and back- seat passengers, we don't know if more front- or back-seat injuries is actually an interesting result.

(D) is wrong because 49/51 and 51/49 splits of seatbelt-to-non-seatbelt-wearers are indistinguishable to us from the perspective of this article.

And, (E) is irrelevant, because in that more than half without serious injury, we don't know a thing about proportions who had seat belts.

Sorry for the confusion on the OA on this problem, and happy problem solving!
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Re: A recent survey of all auto accident victims in Dole County found that  [#permalink]

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23 Jun 2013, 03:59
I was able to read option A by POE. but I still dont understand how option A works out. Can an expert comment pls?
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Re: A recent survey of all auto accident victims in Dole County found that  [#permalink]

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24 Jun 2013, 12:24
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vibhav wrote:
I was able to read option A by POE. but I still dont understand how option A works out. Can an expert comment pls?

This question is quite confusing - it's likely that the wording would be rephrased on the real exam. It's not clearly presented that there are other groups other than the "severely injured" group. What is the source?

The key point here is in how the information is provided and structured. The survey is for those who got into accident. Now, most readers make the incorrect connection between 'accident' and 'severely injured'. They think that 80% of people got into accident and were seriously injured, the remaining 20% did not get into accident and were safe.

That's incorrect.

The way the information is provided, they are saying that of those that are severely injured (we don't know what portion of the accidents resulted in SEVERE injury but let's say 60% for example or 60 people out of 100) -- 80% did not wear seat belts.

That means out of 60 seriously injured people (out of 100 total), 80% of these 60 did not wear seat belts. Or, 48 did not wear seat belts.

What's important to note is that 20% of these 60 (or 12 people) DID wear a seat belt and still got seriously injured.

So to summarize, 60 people were seriously injured (48 did not wear a seat belt while 12 did). The remaining 40 were more mildly injured and we have no data as to who wore or did not wear seat belts.

The argument is that wearing a seatbelt reduces the risk of SERIOUS injury. However, we know that 12 people wore a seatbelt and still got seriously injured. How do we know that wearing seat belt can reduce the risk?

Well, it must be the case that people wearing a seatbelt tended to have more mild injuries (part of the 40-person group, not the 60-person serious injury group).

So can we show that the breakdown for the serious injury was
80% no seat belt
20% seat belt

...and that the breakdown for the mild injury group was
<80% no seat belt and
>20% seat belt?

If so that means if you wear a seat belt, you are more likely to be part of the mild injury group than the serious injury group.
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Re: A recent survey of all auto accident victims in Dole County found that  [#permalink]

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03 Jul 2013, 10:59
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ritula wrote:
A recent survey of all auto accident victims in Dole County found that, of the severely injured drivers and front-seat passengers, 80 percent were not wearing seat belts at the time of their accidents. This indicates that, by wearing seat belts, drivers and front-seat passengers can greatly reduce their risk of being severely injured if they are in an auto accident.

The conclusion above is not properly drawn unless which of the following is true?

(A) Of all the drivers and front-seat passengers in the survey, more than 20 percent were wearing seat belts at the time of their accidents.
(B) Considerably more than 20 percent of drivers and front-seat passengers in Dole County always wear seat belts when traveling by car.
(C) More drivers and front-seat passengers in the survey than rear-seat passengers were very severely injured.
(D) More than half of the drivers and front-seat passengers in the survey were not wearing seat belts at the time of their accidents.
(E) Most of the auto accidents reported to police in Dole County do not involve any serious injury.

A more numeric approach:
The conclusion of the arguement is that by wearing seat-belts, drivers and front-seat passengers can reduce the risk of being .....
Let's assume that out of all the people surveyed,say x, 100 were severly injured. So the remaining were not severly injured(Mild injury,no injury,etc).Now, out of these 100 people, 80 were not wearing seat belts at the time of accident. Thus, 20 were wearing seat belts and still got serious injuries. Now, to re-inforce/buttress the fact that wearing seat-belt greatly reduces the risk of being severly injured[and hence the conclusion of the arguement], the author would need support from the group of people who didn't suffer serious injury because they were wearing seat-belts.
Now, if option A is true, then that means that: # of people wearing seat belts >$$\frac{x}{5}$$ --> # of people wearing seat belts > 20[as x>100 is inherently understood]. This directly means that atleast some of the people who are from the not serious injuries group must have worn seat-belts, thus cementing the conclusion.

Also, as per Option D, we would have the condition : # of people not wearing seat belts >$$\frac{x}{2}$$. Just as above, we have x>100. Thus, # of people not wearing seat belts >50. However, we anyways know that the # of people not wearing seat belts is atleast 80. Thus, this option doesn't really add anything conclusive to cement the conclusion.
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Re: A recent survey of all auto accident victims in Dole County found that  [#permalink]

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04 Jul 2013, 19:53
1
2
ritula wrote:
A recent survey of all auto accident victims in Dole County found that, of the severely injured drivers and front-seat passengers, 80 percent were not wearing seat belts at the time of their accidents. This indicates that, by wearing seat belts, drivers and front-seat passengers can greatly reduce their risk of being severely injured if they are in an auto accident.

The conclusion above is not properly drawn unless which of the following is true?

(A) Of all the drivers and front-seat passengers in the survey, more than 20 percent were wearing seat belts at the time of their accidents.
(B) Considerably more than 20 percent of drivers and front-seat passengers in Dole County always wear seat belts when traveling by car.
(C) More drivers and front-seat passengers in the survey than rear-seat passengers were very severely injured.
(D) More than half of the drivers and front-seat passengers in the survey were not wearing seat belts at the time of their accidents.
(E) Most of the auto accidents reported to police in Dole County do not involve any serious injury.

Responding to a pm:

First let's figure out the conclusion in short: If drivers are in an accident, they can reduce risk of severe injury by wearing seat belts.

Notice that the conclusion focuses on drivers who are in an accident, not on other drivers. The point is that if one is in an accident, seat belt can reduce risk of severe injuries. So to prove it, we need data on all drivers who were in an accident.
When people are in an accident, they either suffer mild injuries or severe injuries (which could lead to death).

So if we know that of all who suffered severe injuries, only 20% were wearing seat belts, it doesn't help us conclude that wearing seat belts reduces risk of severe injuries. We need to know that of all who suffered mild injuries, how many were wearing seat belts. Say, of those who suffered mild injuries, only 10% were wearing seat belts, can we still say that seat belts reduce risk of severe injuries? No. Of those who suffered mild injuries, if 60% were wearing seat belts, it strengthens our conclusion.

Taking numbers, say 100 drivers were in an accident.
50 suffered mild injuries - Say, 30 were wearing seat belts
50 suffered severe injuries - Only 10 were wearing seat belts
We need this data to prove our conclusion - if one wears the seat belt, it reduces the risk of severe injuries.
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Re: A recent survey of all auto accident victims in Dole County found that  [#permalink]

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24 Oct 2013, 16:52
ritula wrote:
A recent survey of all auto accident victims in Dole County found that, of the severely injured drivers and front-seat passengers, 80 percent were not wearing seat belts at the time of their accidents. This indicates that, by wearing seat belts, drivers and front-seat passengers can greatly reduce their risk of being severely injured if they are in an auto accident.

The conclusion above is not properly drawn unless which of the following is true?

(A) Of all the drivers and front-seat passengers in the survey, more than 20 percent were wearing seat belts at the time of their accidents.
(B) Considerably more than 20 percent of drivers and front-seat passengers in Dole County always wear seat belts when traveling by car.
(C) More drivers and front-seat passengers in the survey than rear-seat passengers were very severely injured.
(D) More than half of the drivers and front-seat passengers in the survey were not wearing seat belts at the time of their accidents.
(E) Most of the auto accidents reported to police in Dole County do not involve any serious injury.

OK, let's make this one rain.

Conclusion: By wearing seat belts,drivers and front-seat passengers can reduce their risk of being severely injured
Premise: A survey of all auto accident victims found that, of the severely injured drivers and front-seat passengers, 80 percent were not wearing seat belts at the time of their accidents

So what do we have here? The survey stated that 80% of the injured were not wearing seat belts, so that means that we need to show that there was some percentage that were in fact wearing seat belts.

OK let's see what we've got here

(A) Of all the drivers and front-seat passengers in the survey, more than 20 percent were wearing seat belts at the time of their accidents.I like this one. This is very similar to what I was looking for.
(B) Considerably more than 20 percent of drivers and front-seat passengers in Dole County always wear seat belts when traveling by car>> Always wear? Well, we don't really need this information we need to know about the ones being injured. So out you go
(C) More drivers and front-seat passengers in the survey than rear-seat passengers were very severely injured ---> Unessessary distinction here. Cleraly out
(D) More than half of the drivers and front-seat passengers in the survey were not wearing seat belts at the time of their accidents---> More than half were not wearing seatbelts, Could be. I'll leave it in.
(E) Most of the auto accidents reported to police in Dole County do not involve any serious injury.[/quote]>> Irrelevant. Out

Between A and D now.
A says that of all the the D and P >20% were wearing seatbelts
D says that of all the D and P >50% were NOT wearing setabelts.

Premise says that 80% of the injured.
I'm going with A on this one, it fits the argument better

Hence(A)

Hope it helps
Cheers!
J
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Re: A recent survey of all auto accident victims in Dole County found that  [#permalink]

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04 May 2014, 00:48
jitgoel wrote:
A recent survey of all auto accident victims in Dole County found that, of the severely injured drivers and front-seat passengers, 80 percent were not wearing seat belts at the time of their accidents. This indicates that, by wearing seat belts, drivers and front-seat passengers can greatly reduce their risk of being severely injured if they are in an auto accident.
The conclusion above is not properly drawn unless which of the following is true?
(A) Of all the drivers and front-seat passengers in the survey, more than 20 percent were wearing seat belts at the time of their accidents.
(B)Considerably more than 20 percent of drivers and front-seat passengers in Dole County always wear seat belts when traveling by car.
(C) More drivers and front-seat passengers in the survey than rear-seat passengers were very severely injured.
(D) More than half of the drivers and front-seat passengers in the survey were not wearing seat belts at the time of their accidents.
(E) Most of the auto accidents reported to police in Dole County do not involve any serious injury.

The question stem is:The conclusion above is not properly drawn unless which of the following is true. It means it is a justify conclusion type of question (according to the Critical Reasoning Bible). In justify conclusion type of questions we need to link any new elements in the conclusion and the premise and ignore the common ones. The correct answer need not contain the common elements of the conclusion and the premise.

So in this case,
The premise:of the severely injured drivers and front-seat passengers, 80 percent were not wearing seat belts at the time of their accidents.
Conclusion:by wearing seat belts, drivers and front-seat passengers can greatly reduce their risk of being severely injured if they are in an auto accident
New thing from the conclusion and the premise is the percentage figure, so the correct answer should contain something related to this percentage figure. If we look at the answer choices
there are only two which mention the percentage figures Choice (A) and Choice (B).

Choice B is not the answer since we are concerned with the number of drivers and front-seat passengers wearing seat belts at the time of accident, which is what A says. The word "always" in B also makes this choice wrong.

Do let me know what you think of the reasoning provided above.
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Re: A recent survey of all auto accident victims in Dole County found that  [#permalink]

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09 Jul 2014, 11:05
1
suppose in a town there are 100 people driving vehicles, 40( more than 20 %) wore seat belts , 60 did'nt.
accidents take place.... 10 result in serious cases..... 2 were wearing seat belts 8 were not.....
chances of serious accident----- for those with seat belt- 2/40 ie 5%
-------for those without seat belts- 8/60 ie 13.5 %.

hence conclusion true.....ans = A.............
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Re: A recent survey of all auto accident victims in Dole County found that  [#permalink]

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05 Jul 2015, 23:58
ritula wrote:
A recent survey of all auto accident victims in Dole County found that, of the severely injured drivers and front-seat passengers, 80 percent were not wearing seat belts at the time of their accidents. This indicates that, by wearing seat belts, drivers and front-seat passengers can greatly reduce their risk of being severely injured if they are in an auto accident.

The conclusion above is not properly drawn unless which of the following is true?

(A) Of all the drivers and front-seat passengers in the survey, more than 20 percent were wearing seat belts at the time of their accidents.
(B) Considerably more than 20 percent of drivers and front-seat passengers in Dole County always wear seat belts when traveling by car.
(C) More drivers and front-seat passengers in the survey than rear-seat passengers were very severely injured.
(D) More than half of the drivers and front-seat passengers in the survey were not wearing seat belts at the time of their accidents.
(E) Most of the auto accidents reported to police in Dole County do not involve any serious injury.

The scope of the argument is
1) "ALL" auto accidents. It is not restricted to a particular type of vehicle, e.g. a truck or a car or a motorcycle.
2) "Severely injured drivers and front seat passengers" only. Nothing is mentioned about the rear seat drivers.

Based on the given fact about the seat belt status of a given percentage of severely injured drivers and front seat passengers, to conclude that wearing seat belts would reduce severity of accidents, the argument must assume that if there is a scenario where wearing seat belts considerably reduces severe accidents, the same can be emulated in all scenarios with the same result.

(A) Of all the drivers and front-seat passengers in the survey, more than 20 percent were wearing seat belts at the time of their accidents.
This option is completely within the scope of the argument. More than 20% could mean 80% or could mean 21%.
Let us say 80% were wearing seat belts and 20% did not. That means a total of 25% accidents were severe of which 80%(20% of the total accidents) were found to not wear the seat belts. Hence going by the fact that the remaining 75% accidents which were not severe AND the drivers and front seat passengers werewearing the seat belts, it is a valid assumption that wearing seat belts does reduce severity of accidents.
Let us say 21% were wearing the seat belts and 79% did not. Doing a similar calculation, it is clear that 98.75% accidents were severe, thus indicating that wearing seat belts does not necessarily mean reduced severity.

The above analysis of (Option A) assumes that all accidents involving no seat belts were severe. Without this assumption, the number of possible scenarios increases, but eventually in at least one scenario, the fact that more than 20% were wearing seat belts at the time of the accident does not help strengthen the conclusion. Hence in my opinion,
this is wrong option.

(B) Considerably more than 20 percent of drivers and front-seat passengers in Dole County always wear seat belts when traveling by car.
The word "considerably" removes the ambiguity of meaning of more than 20% to be 80% or 21%. Although we do not know exactly what is this considerable figure, but we can rest assured that it is quite sizable.
But this option is restricted to cars. So should we therefore remove it from our consideration using POE? I think NO.
Reason being, we have established that the author is trying to emulate the effectiveness of one scenario across all possible scenarios.
Let us give some numbers now. Let us say this considerable number is 50%. Hence, going by the assumption in the analysis for option A, the remaining 50% of drivers and front-seat passengers who did not wear the seat belts makes the total of severe accidents, 62.5% of all accidents. This means, 38.5% accidents were not severe AND the drivers and front seat passengers were wearing the seat belts.
Although all these figures are restricted to car accidents,
it is a good candidate for forming the conclusion that if the scenario of the 38.5% accidents is emulated, the severity would reduce.

(C) More drivers and front-seat passengers in the survey than rear-seat passengers were very severely injured.
The seat belt status of the rear-seat passengers is not known. This option does not indicate in any way as to why the author would conclude wearing seat belts as an option to reduce severity of accidents. Out of Scope

(D) More than half of the drivers and front-seat passengers in the survey were not wearing seat belts at the time of their accidents.
Going by the assumption used to analyze options A and B, this option indicates that very less percentage of drivers and front-seat passengers were seat belts, thus not providing strong grounds to make the conclusion. This weakens the argument.

(E) Most of the auto accidents reported to police in Dole County do not involve any serious injury.
Clearly Out of Scope
Re: A recent survey of all auto accident victims in Dole County found that &nbs [#permalink] 05 Jul 2015, 23:58

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