Question from GMAPPrep

This topic has expert replies
Source: — Critical Reasoning |

User avatar
Master | Next Rank: 500 Posts
Posts: 253
Joined: Fri Dec 26, 2008 8:39 pm
Thanked: 8 times
Followed by:1 members

by BlindVision » Tue Aug 02, 2011 4:43 pm
A
Life is a Test

User avatar
Legendary Member
Posts: 1077
Joined: Mon Dec 13, 2010 1:44 am
Thanked: 118 times
Followed by:33 members
GMAT Score:710

by bblast » Fri Aug 05, 2011 12:04 am
hi, in such questions you are trying to prove that the sample used by the author is representative of the author's conclusion.


this is a very common question type- so make sure u understand that the correct option here. Option A tells us that the sample under study here was not biased towards smoking. i.e depressed people were not more likely to smoke than non depressed one's.


Thus the conclusion of the study that smoking = depression is streghthened.

This type of statistical evidence reasoning is very common on weaken questions.
Cheers !!

Quant 47-Striving for 50
Verbal 34-Striving for 40

My gmat journey :
https://www.beatthegmat.com/710-bblast-s ... 90735.html
My take on the GMAT RC :
https://www.beatthegmat.com/ways-to-bbla ... 90808.html
How to prepare before your MBA:
https://www.youtube.com/watch?v=upz46D7 ... TWBZF14TKW_

User avatar
Master | Next Rank: 500 Posts
Posts: 344
Joined: Mon Sep 14, 2009 5:40 am
Thanked: 28 times
Followed by:3 members
GMAT Score:700

by sunnyjohn » Fri Aug 05, 2011 12:16 am
Hi Smodak,

This is very common type of GMAT question. This belongs to cause and effect category.

F1: A study of students who have never smoked.
F2: Study intention was to track the smoking and it after effects on students.
F3: After one year, those who started to smoke were more depressed than who don't.

Conclusion: Smoking cause Depression.

One of the best way to strengthen this argument is - show that the relationship is NOT REVERSED.
Or - Eliminate the possibility of "Depression cause people to smoke."

If you have to weaken this argument, then do the reverse. Show the relationship is REVERSE.
Or - Show that "Depression cause people to smoke."

If you decode option A, it is clearly stating the fact that relationship is not reverse.

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 645
Joined: Mon Jul 26, 2010 12:42 pm
Location: US
Thanked: 527 times
Followed by:227 members

by e-GMAT » Fri Aug 05, 2011 11:53 am
While these pointers to answer causal questions are helpful tips, one must remember that the key role of a strengthener is that it makes the conclusion more likely. This is because, unless you understand this, you will not be able to apply the rules well.

This argument: This argument concludes that smoking contributes to depression in teenagers. The conclusion is based on the data from the study that states that people who smoke are 4 times as likely to be depressed.

When you see a question like this, you should ask yourself.. is it likely that people who take up smoking are depressed in the first place. If this is so, then it is depression that causes people to take up smoking not the other way round. Therefore, a strengthener would be something that discounts the possibility described above. Choice A does exactly that.

Think of a similar passage..

Students who take remedial classes are twice as likely to fail than people who dont. Hence, remedial classes cause students to fail.

In the argument above, one would ask.. Are students who join remedial classes more likely to fail in the first place.