Critical Reasoning

The use of automobile safety seats by children aged 4 and under has nearly doubled in the past 8 years. It is clear that this increase has prevented child fatalities that otherwise would have occurred, because although the number of children aged 4 and under who were killed while riding in cars involved in accidents rose 10 percent over the past 8 years, the total number of serious automobile accidents rose by 20 percent during that period.
Which one of the following, if true, most strengthens the argument?
(A) Some of the automobile safety seats purchased for children under 4 continue to be used after the child reaches the age of 5.
(B) The proportion of serious automobile accidents involving child passengers has remained constant over the past 8 years.
(C) Children are taking more trips in cars today than they were 8 years ago, but the average total time they spend in cars has remained constant.
(D) The sharpest increase in the use of automobile safety seats over the past 8 years has been for children over the age of 2.
(E) The number of fatalities among adults involved in automobile accidents rose by 10 percent over the past 8 years.

frankly speaking i used only poe to solve this one although could not understand the question here....

a--> child reaching age of 5 is outside scope of argument
c-->does not impact the arg as it talks about the fatalities and acciedents
d-->under the age of 2 makes it outside the scope
e-->need explanation
b-->need explanation

Thanks

ssgmatter wrote:The use of automobile safety seats by children aged 4 and under has nearly doubled in the past 8 years. It is clear that this increase has prevented child fatalities that otherwise would have occurred, because although the number of children aged 4 and under who were killed while riding in cars involved in accidents rose 10 percent over the past 8 years, the total number of serious automobile accidents rose by 20 percent during that period.
Which one of the following, if true, most strengthens the argument?
(A) Some of the automobile safety seats purchased for children under 4 continue to be used after the child reaches the age of 5.
(B) The proportion of serious automobile accidents involving child passengers has remained constant over the past 8 years.
(C) Children are taking more trips in cars today than they were 8 years ago, but the average total time they spend in cars has remained constant.
(D) The sharpest increase in the use of automobile safety seats over the past 8 years has been for children over the age of 2.
(E) The number of fatalities among adults involved in automobile accidents rose by 10 percent over the past 8 years.

Hi,

what we have here is a classic scope shift - the evidence and the conclusion talk about different things. Accordingly, the author must be assuming that they're connected.

The conclusion is that child seats are saving lives of the under-4 crowd.

We have two pieces of evidence: the number of under-4 deaths has gone up 10% and the number of serious accidents has gone up 20%.

At first this might seem persuasive, but we need to recognize the shift: we know that the total number of serious accidents has increased by 20%, but we don't know if the number of serious accidents involving under-4s has gone up at all.

So, in order for the conclusion to follow from the evidence, the author must be assuming that the number of accidents involving under-4s has increased by more than 10% (to offset the increase in the number of deaths). Since this is a strengthening question, we want an answer that backs up the author's assumption.

The only choice that connects accidents in general to accidents of under-4s is (B), which must therefore be the correct choice.

Stuart Kovinsky wrote:

ssgmatter wrote:The use of automobile safety seats by children aged 4 and under has nearly doubled in the past 8 years. It is clear that this increase has prevented child fatalities that otherwise would have occurred, because although the number of children aged 4 and under who were killed while riding in cars involved in accidents rose 10 percent over the past 8 years, the total number of serious automobile accidents rose by 20 percent during that period.
Which one of the following, if true, most strengthens the argument?
(A) Some of the automobile safety seats purchased for children under 4 continue to be used after the child reaches the age of 5.
(B) The proportion of serious automobile accidents involving child passengers has remained constant over the past 8 years.
(C) Children are taking more trips in cars today than they were 8 years ago, but the average total time they spend in cars has remained constant.
(D) The sharpest increase in the use of automobile safety seats over the past 8 years has been for children over the age of 2.
(E) The number of fatalities among adults involved in automobile accidents rose by 10 percent over the past 8 years.

Hi,

what we have here is a classic scope shift - the evidence and the conclusion talk about different things. Accordingly, the author must be assuming that they're connected.

The conclusion is that child seats are saving lives of the under-4 crowd.

We have two pieces of evidence: the number of under-4 deaths has gone up 10% and the number of serious accidents has gone up 20%.

At first this might seem persuasive, but we need to recognize the shift: we know that the total number of serious accidents has increased by 20%, but we don't know if the number of serious accidents involving under-4s has gone up at all.

So, in order for the conclusion to follow from the evidence, the author must be assuming that the number of accidents involving under-4s has increased by more than 10% (to offset the increase in the number of deaths). Since this is a strengthening question, we want an answer that backs up the author's assumption.

The only choice that connects accidents in general to accidents of under-4s is (B), which must therefore be the correct choice.

Thanks Stuart for your thoughts.

I am just confused about this statements in your explanation....please elaborate a more on this...

'At first this might seem persuasive, but we need to recognize the shift: we know that the total number of serious accidents has increased by 20%, but we don't know if the number of serious accidents involving under-4s has gone up at all.'

we are given accidents in terms of percentage...
there is a possibility that percentage might decrease but actual numbers might increase
B says that proportion has remained constant. hence percentage declne actually implied number reduction

outreach wrote:we are given accidents in terms of percentage...
there is a possibility that percentage might decrease but actual numbers might increase
B says that proportion has remained constant. hence percentage declne actually implied number reduction

Bhai Amar,

Please explain in details.

ssgmatter wrote:The use of automobile safety seats by children aged 4 and under has nearly doubled in the past 8 years. It is clear that this increase has prevented child fatalities that otherwise would have occurred, because although the number of children aged 4 and under who were killed while riding in cars involved in accidents rose 10 percent over the past 8 years, the total number of serious automobile accidents rose by 20 percent during that period.
Which one of the following, if true, most strengthens the argument?
(A) Some of the automobile safety seats purchased for children under 4 continue to be used after the child reaches the age of 5.
(B) The proportion of serious automobile accidents involving child passengers has remained constant over the past 8 years.
(C) Children are taking more trips in cars today than they were 8 years ago, but the average total time they spend in cars has remained constant.
(D) The sharpest increase in the use of automobile safety seats over the past 8 years has been for children over the age of 2.
(E) The number of fatalities among adults involved in automobile accidents rose by 10 percent over the past 8 years.

Two objections to this line of reasoning come to mind:

Cars may have undergone changes that make them more crash-resistant, not only for young children but also for other passengers. Hospitals and ambulances may be better equipped to save the lives of crash victims. These possibilities are made more plausible by E: why hasn't the number of fatalities among adults risen by 20%? Adults do not use these safety seats! Thus E weakens the argument.

What if children make up a smallest proportion of crash victims than before? It may be that people now make proportionally fewer trips with children, leaving them with grandparents or at kindergardens. Thus a suprisingly small increase in the number of child fatalities could be explained by factors other than the safety seats. B effectively counters this objection and thus strengthens the arugment.

@Stuart ...can u explain a bit more?

Thanks,
Aditya

i will not say that i am confident on this question type....i am still not so much clear about this question..Gurus please explain in little more details/

Thanks!

You should make an effort to explain precisely what you don't understand or on what you need elaboration. Do you understand the arugment, and why somebody might find it convincing?

adi_800 wrote:@Stuart ...can u explain a bit more?

Thanks,
Aditya

Hi,

if you ask a more specific question, I'm happy to help out - but it's very hard to respond to "explain a bit more".

ssgmatter wrote:
Thanks Stuart for your thoughts.

I am just confused about this statements in your explanation....please elaborate a more on this...

'At first this might seem persuasive, but we need to recognize the shift: we know that the total number of serious accidents has increased by 20%, but we don't know if the number of serious accidents involving under-4s has gone up at all.'

Sure.

The author's evidence is that the total number of serious car accidents has gone up by 20% and the number of deaths involving young children has only gone up by 10%. The author concludes that young children are safer than they used to be.

However, the author overlooks the possibility that all of those extra car accidents may not involve young children. For example, it could be true that:

2002: 100 serious accidents, 50 involved small children, 10 little kids were killed.
2010: 120 serious accidents, 40 involved small children, 11 little kids were killed.

The numbers reflect a 10% increase in child deaths and a 20% increase in total number of serious accidents, so they go along with the evidence presented by the author. However, if these numbers are accurate, the death rate for little kids has actually gone up from 10/50 to 11/40, showing that children are actually in more danger now, not safer.

In order for the conclusion to follow from the evidence, the author has to be assuming that the proportion of serious accidents involving small children has not changed in this fashion. (B) backs up that assumption, so it's the right answer to a strengthening question.

stuart...
That was Chrystal clear...My doubts were solved..
Thanks...