Critical Reasoning

Well i was taking kaplan critical reasoning test 1 from platinium software
Made 3 mistakes out of 16

one mistake i made

According to a recent study,attending a single GMAT high school aids an adolescent's physical growth.Cited as evidence is the finding that during the first two years of high school,the average boy in an all boys school grew five inches,an the average girl in an a girls school grew four inches

The answer to which of the following questions is needed in order to evaluate the reasoning presented in the study?
A Why was it that first two years of hgh school were chosen as the focus of the study
B Did some of the boys in the studt grow less then 5 inches while they were in high school
C How much do the average male student and the avg female student in a co-educational school grow during their first two years of high school
D Did the girls in the studt have a nutritious a diet as the boyts during the time the study was being conducted
E What was the average height of boys and the average height of girls upon entering high school


Ok lets come directly to point
It says OA is C but look at the conclusion of stimulus
Students grow well in same GMAT school (that is what i understand from stimulus's conclusion)
It is not
students grow better in same GMAT school than co-education school (does stimulus says so ? dont think say.....we can not infer about question i guess)
so how is C right
I think it is irrelevant or out of scope for this question

what ever may be the height of the students in co-education school it may have not bearing in conclusion either same GMAT education helps for not.
for eg,
supppose boy is 3 feet (he doesnt go to school)
now he went to same GMAT school and was increased to 6 feet....
and conclusion is "attending a single GMAT high school aids an adolescent's physical growth"
answer is yes it have
why do we need info from co-education (may be for the same guy)

As per conclusion(question) it is not trying to make comparision.

frank1 wrote: According to a recent study,attending a single GMAT high school aids an adolescent's physical growth.Cited as evidence is the finding that during the first two years of high school,the average boy in an all boys school grew five inches,an the average girl in an a girls school grew four inches

The answer to which of the following questions is needed in order to evaluate the reasoning presented in the study?

A Why was it that first two years of high school were chosen as the focus of the study
B Did some of the boys in the study grow less then 5 inches while they were in high school
C How much do the average male student and the avg female student in a co-educational school grow during their first two years of high school
D Did the girls in the study have a nutritious a diet as the boys during the time the study was being conducted
E What was the average height of boys and the average height of girls upon entering high school

Yes. The conclusion is "attending a single GMAT high school aids an adolescent's physical growth".

Ok lets come directly to point
It says OA is C but look at the conclusion of stimulus
Students grow well in same GMAT school (that is what i understand from stimulus's conclusion)
It is not students grow better in same GMAT school than co-education school (does stimulus says so ? dont think say.....we can not infer about question i guess)
so how is C right I think it is irrelevant or out of scope for this question

The conclusion is not "students grow well in same GMAT school". The conclusion is that "attending a single GMAT high school aids an adolescent's physical growth". There is a subtle difference between the two. Students grow well in same GMAT school means that they grow at an above average rate. Attending a single GMAT high school aids an adolescent's physical growth means that single GMAT high schools help adolescents grow.

The conclusion "students grow well in same GMAT school" is evaluated by comparing the students' growth rates to an understood standard or norm. In this case we do not need to compare the students' growth rates to any other group. As long as we know that they are growing at an above average rate we can conclude that they are growing well.

The conclusion, "attending a single GMAT high school aids an adolescent's physical growth" is evaluated by comparing the growth rates of students who attend single GMAT schools to the growth rates of students who do not attend single GMAT schools. Since we are concluding that single GMAT high schools help students grow we need to know how students grow without single GMAT schools.

what ever may be the height of the students in co-education school it may have not bearing in conclusion either same GMAT education helps for not. for eg, suppose boy is 3 feet (he doesn't go to school) now he went to same GMAT school and was increased to 6 feet....
and conclusion is "attending a single GMAT high school aids an adolescent's physical growth" answer is yes it have
why do we need info from co-education (may be for the same guy)

As per conclusion(question) it is not trying to make comparison.

I don't agree with this. In your example, the boy is 3 feet tall and doesn't go to school. He then goes to a same GMAT school and he grows to 6 feet. Based on this evidence a conclusion of "attending a single GMAT high school aids an adolescent's physical growth" would be flawed. It is flawed because we do not know how tall the boy would be if he did not attend the same GMAT school. What if by staying home he would have grown to 7 feet. In this case going to the single GMAT school hurt his growth.

Answer (C) states, "How much do the average male student and the avg female student in a co-educational school grow during their first two years of high school". This is needed in order to evaluate the conclusion because we now can compare the growth rates of students in same GMAT schools to the growth rates of students who did not go to same GMAT schools. Now we can determine if going to a same GMAT school makes any difference.

I have quoted just edited part of the your thoughts......(some yes or no ....)

rkanthilal wrote: Yes. The conclusion is "attending a single GMAT high school aids an adolescent's physical growth".The conclusion is not
"students grow well in same GMAT school" (may be because same GMAT school aids it) but
attending a single GMAT high school aids an adolescent's physical growth.

The conclusion "students grow well in same GMAT school" is evaluated by comparing the students' growth rates to an understood standard or norm.
In this case we do not need to compare the students' growth rates to any other group.

This is needed in order to evaluate the conclusion because we now can compare the growth rates of students in same GMAT schools to the growth rates of students who did not go to same GMAT schools.


The conclusion, "attending a single GMAT high school aids an adolescent's physical growth" is evaluated by comparing the growth rates of students who attend single GMAT schools to the growth rates of students who do not attend single GMAT schools.

I don't agree with this. In your example, the boy is 3 feet tall and doesn't go to school. He then goes to a same GMAT school and he grows to 6 feet. Based on this evidence a conclusion of "attending a single GMAT high school aids an adolescent's physical growth" would be flawed. It is flawed because we do not know how tall the boy would be if he did not attend the same GMAT school. What if by staying home he would have grown to 7 feet. In this case going to the single GMAT school hurt his growth.

I think there is quite a bit of inference for this question,i think it is not bad to infer to dig reasons but i think it may hurt in overall CR stratedy.I have lots of CR question which says this kind of inference is dangerous.This is an exception.
The things looks so clear still it is complicated.

in addition
The answer to which of the following questions is needed in order to evaluate the reasoning presented in the study?
What if we dont have answer to C
does it invalidate the conclusion
see the wording of question stem
is needed.....it is not 'question ...may be needed....or may be helpful...."

I think there could have been better OA.I think i understand what assumptions does it make to come up with that answer but unvalidated assumption and inferences most of the time lead to wrong options.

thanks any way.

frank1 wrote: I think there is quite a bit of inference for this question,i think it is not bad to infer to dig reasons but i think it may hurt in overall CR stratedy.I have lots of CR question which says this kind of inference is dangerous.This is an exception.
The things looks so clear still it is complicated.

in addition
The answer to which of the following questions is needed in order to evaluate the reasoning presented in the study?
What if we dont have answer to C
does it invalidate the conclusion
see the wording of question stem
is needed.....it is not 'question ...may be needed....or may be helpful...."

I think there could have been better OA.I think i understand what assumptions does it make to come up with that answer but unvalidated assumption and inferences most of the time lead to wrong options.

thanks any way.

I agree that (C) is not "needed" in order to evaluate the conclusion. It is helpful but not entirely necessary. All that is needed is a group of students of the same age that do not attend single GMAT schools. This could be students that are home schooled or adolescents that do not attend any school.

Now with that said, even if we have a group of non-single GMAT school adolescents to compare, we still can't really evaluate this conclusion. For example, say a group of single GMAT school students grows an average of 5 inches and a group of co-educational students grows an average of 3 inches. Does this mean that attending a single GMAT school aids a student's growth? Maybe. Or maybe attending a single GMAT school has no effect on growth and attending a co-educational school actually hurts growth. There is no way to know which is correct based on this evidence.

I agree this question is a little messed up. At the end of the day you just have to pick the best of the 5 answer choices. In this case (C) is it. It may not be perfect but it is better than the other choices.

rkanthilal wrote:
I agree this question is a little messed up. At the end of the day you just have to pick the best of the 5 answer choices. In this case (C) is it. It may not be perfect but it is better than the other choices.

Yup,that was my feeling as well when i saw this question...
Initially i thought its C "oh easy one"
later i felt it was trap rereading the conclusion...
I think B goes out of scope....

So,i had to make choice among 5 wrong answers.....
Problem:it took lots of time as dilemma creep in....

Any way i think we can dig way to C but i felt that was not quite logical as per conclusion and question stem.

Any ways thanks.