It is currently 17 Oct 2017, 22:23

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# A recent study of college students shows that, contrary to

Author Message
TAGS:

### Hide Tags

Intern
Joined: 18 May 2008
Posts: 3

Kudos [?]: 24 [4], given: 0

A recent study of college students shows that, contrary to [#permalink]

### Show Tags

06 Jul 2008, 18:16
4
KUDOS
14
This post was
BOOKMARKED
00:00

Difficulty:

95% (hard)

Question Stats:

38% (01:23) correct 62% (01:23) wrong based on 1155 sessions

### HideShow timer Statistics

A recent study of college students shows that, contrary to predicted results, special nutritional planning does not positively affect students’ grades. Sixty students, half of whom were given a nutritionally balanced diet, had grades no higher than did those students who were not placed on the diet plan.

Which of the following, if true, is most useful in determining the accuracy of the study described above?

(A) Performance of business executives was shown to improve drastically after major alterations were made in their diets.
(B) Honors students, after altering their diets, maintained that they did not change their study habits.
(C) Students who participated in various fitness regimens found that their grades improved appreciably after they altered their exercise habits.
(D) High school students who previously had low grades found that after they altered their diets, their grades improved dramatically.
(E) All of the college students who volunteered for the study were either in their first or second year of college.

I marked the answer at ii), because if no changes were made to the study habits then we can conclude that there was no effect of study habits on the study, hence effect of diet can be correctly determined (Whether it had some effect or not). But this answer is wrong . Can anybody explain the correct answer).
[Reveal] Spoiler: OA

Kudos [?]: 24 [4], given: 0

VP
Joined: 05 Jul 2008
Posts: 1402

Kudos [?]: 437 [6], given: 1

### Show Tags

06 Jul 2008, 18:25
6
KUDOS
contrary to predicted results, special nutritional planning does not positively affect students’ grades

Predicted results would have been special nutritional planning positively affect students’ grades

C & E are out of scope

Among A, B and D

A is using business executive performance improvement. We don't know whether we can relate real time performance improvement to grades (ironically like GMAT and real time) Still I would hold it for now

I agree with your reasoning on B but we simply don't know whether it had any effect or not. But it sounds as if diet did not had any effect Also, we are talking about a subset of students

D is saying low grade HS students with the new diet improved their grades

Look at the Q again.

Which of the following, if true, is most useful in determining the accuracy of the study described above?

D stands on the expected side of results. Probably study is wrong or this case of college students is an anomaly

Kudos [?]: 437 [6], given: 1

VP
Joined: 03 Apr 2007
Posts: 1340

Kudos [?]: 831 [5], given: 10

### Show Tags

07 Jul 2008, 09:54
5
KUDOS
bhatiasanjay01 wrote:
A recent study of college students shows that, contrary to predicted results, special nutritional planning does not positively affect students’ grades. Sixty students, half of whom were given a nutritionally balanced diet, had grades no higher than did those students who were not placed on the diet plan.

Which of the following, if true, is most useful in determining the accuracy of the study described above?

i) Performance of business executives was shown to improve drastically after major alterations were made in their diets.
ii)Honors students, after altering their diets, maintained that they did not change their study habits.
iii)Students who participated in various fitness regimens found that their grades improved appreciably after they altered their exercise habits.
iv) High school students who previously had low grades found that after they altered their diets, their grades improved dramatically.
v) All of the college students who volunteered for the study were either in their first or second year of college.

I marked the answer at ii), because if no changes were made to the study habits then we can conclude that there was no effect of study habits on the study, hence effect of diet can be correctly determined (Whether it had some effect or not). But this answer is wrong . Can anybody explain the correct answer).

Conclusion: special nutritional planning does not positively affect students’ grades.
Evidence:Sixty students, half of whom were given a nutritionally balanced diet, had grades no higher than did those students who were not placed on the diet plan.

The evidence here is weak becuase it provides no details about the student's grade before and after the intake of special diet.Only D brings in information to say students with previously lower grades performed well after they started takin in special diet and refute the conclusion that special diet donot affect student's growth. This answer choice can used to measure the accuracy of this conclusion made in the argument.

D

Kudos [?]: 831 [5], given: 10

Manager
Affiliations: University of Tehran
Joined: 06 Feb 2011
Posts: 200

Kudos [?]: 38 [2], given: 57

Location: Iran (Islamic Republic of)
Concentration: Marketing
Schools: Wharton
GMAT 1: 680 Q45 V38
GPA: 4
WE: Marketing (Retail)

### Show Tags

01 Aug 2011, 09:58
2
KUDOS
Wait... So the fight is so hot b/w D and E. Let us analyze the weak points and strength points of each choice in "determining the accuracy of the study described above":

E: What makes this choice suitable is the fact that it points at some weaknesses in the methodology. Right. So let's put this choice aside for now since it may be the best choice. So, this choice helps us evaluate the accuracy of the study by evaluating the methodology. The methodology in part determines the accuracy of a study.

D:
The problem with E is that since it talks about a test result that was drawn about HIGHSCHOOLS students, it may be considered IRRELEVANT. BUT, on it's good side, choice E states a result from another study-no matter with what kind of subject/sample, that directly stands AGAINST that of the main study. Right? IanStewart, you are right that choice E is an obvious weakener to the conclusion, but what's wrong with it? This fact can not prevent this choice from "determining the accuracy of the study described above"? Not only it's not prevented but also weakening the results, and determining the accuracy of the results of a study are two concepts so close to each other. If we can weaken a conclusion, the perceived accuracy will be decreased.

The golden point is this: Look at the stem again; it says: A recent study of college students shows that, contrary to predicted results, special nutritional planning does not positively affect STUDENT'S grades. The counterargument (what we are to determine the accuracy of the results of a study against it) is about students' performance in general, NOT just performance of COLLEGE students. So a hypothesis about any kind of STUDENTS' performance can be tested by studying ANY KIND of students.

In sum, my choice is D. Though both D and E aim at accuracy of the conclusion, while E focuses on the defects of methodology, D focuses on the DIRECT opposite results found from another VALID study. Do not forget the point: we are talking about a conclusion about ALL students.

What is the source of this question?
_________________

Ambition, Motivation and Determination: the three "tion"s that lead to PERFECTION.

World! Respect Iran and Iranians as they respect you! Leave the governments with their own.

Kudos [?]: 38 [2], given: 57

Director
Joined: 26 Jul 2007
Posts: 535

Kudos [?]: 180 [1], given: 0

Schools: Stern, McCombs, Marshall, Wharton

### Show Tags

07 Jul 2008, 06:09
1
KUDOS

Which of the following, if true, is most useful in determining the accuracy of the study described above?

We are only concerned about the accuracy of the study. The study looked at 60 students. If these 60 students were not a random group then the study would not be accurate. For example half the students could be seniors who tend to get steady grades because they have made it to their senior year and the other half could be freshmen whose grades are all over the place.

v) All of the college students who volunteered for the study were either in their first or second year of college.

This is the only answer that adds to the validity of the study sample.

Kudos [?]: 180 [1], given: 0

Director
Joined: 26 Jul 2007
Posts: 535

Kudos [?]: 180 [1], given: 0

Schools: Stern, McCombs, Marshall, Wharton

### Show Tags

07 Jul 2008, 06:31
1
KUDOS
chan4312 wrote:
A recent study of college students shows that, contrary to predicted results, special nutritional planning does not positively affect students’ grades. Sixty students, half of whom were given a nutritionally balanced diet, had grades no higher than did those students who were not placed on the diet plan.

Which of the following, if true, is most useful in determining the accuracy of the study described above?

i) Performance of business executives was shown to improve drastically after major alterations were made in their diets. irrelevant
ii)Honors students, after altering their diets, maintained that they did not change their study habits. Not talking about study habits.Also, Unchanged study habits may not guarantee same high grades.
iii)Students who participated in various fitness regimens found that their grades improved appreciably after they altered their exercise habits. irrelevant
iv) High school students who previously had low grades found that after they altered their diets, their grades improved dramatically. tells us precisely whether argument's conclusion is accurate or not.
v) All of the college students who volunteered for the study were either in their first or second year of college.
irrelevant

IMO D

How does that affect the accuracy of this test?

If I do a test of college students. And I ask you to comment on the accuracy of my test on college students and you tell me you did a test on high school students and got different results. How does that affect the ACCURACY of my test? Wouldn't you have to focus on my methods to comment on the accuracy of my test?

To me we are only concerned with the accuracy of the study and not the results.

Kudos [?]: 180 [1], given: 0

GMAT Tutor
Joined: 24 Jun 2008
Posts: 1339

Kudos [?]: 1952 [1], given: 6

### Show Tags

07 Jul 2008, 09:58
1
KUDOS
Expert's post
Interesting question.

bhatiasanjay01 wrote:
A recent study of college students shows that, contrary to predicted results, special nutritional planning does not positively affect students’ grades. Sixty students, half of whom were given a nutritionally balanced diet, had grades no higher than did those students who were not placed on the diet plan.

In blue, I've highlighted the conclusion that is drawn. Is this conclusion part of the study? We don't know. In any case, it's a strange conclusion: from a study of only college students, the writer concludes that nutrition "does not positively affect students’ grades" in general. If you wanted to weaken the conclusion, answer D is a clear choice:

bhatiasanjay01 wrote:
iv) High school students who previously had low grades found that after they altered their diets, their grades improved dramatically.

But weakening the conclusion is not what we're asked to do. The question is:

bhatiasanjay01 wrote:
Which of the following, if true, is most useful in determining the accuracy of the study described above?

I highlighted the part of the stem that refers to the study in red. We're asked to assess the accuracy of the study itself, not the conclusion. We can ignore what I've highlighted in blue. The only answer that refers to the methodology of the study (research methods, population that was studied, etc), is E:

bhatiasanjay01 wrote:
v) All of the college students who volunteered for the study were either in their first or second year of college.

Those studied were volunteers- the sample isn't random- and they were from a particular subset of the overall population. This could affect the vailidity of the study; a properly conducted study might reveal different results. So I agree with gixxer here; the correct answer should be E.
_________________

GMAT Tutor in Toronto

If you are looking for online GMAT math tutoring, or if you are interested in buying my advanced Quant books and problem sets, please contact me at ianstewartgmat at gmail.com

Last edited by IanStewart on 07 Jul 2008, 09:59, edited 1 time in total.

Kudos [?]: 1952 [1], given: 6

Senior Manager
Joined: 20 Jul 2010
Posts: 258

Kudos [?]: 101 [1], given: 9

### Show Tags

28 Jul 2010, 05:22
1
KUDOS
Even I wonder how it can be D. D says they altered the diet. It doesn't say they went on balanced diet which showed positive grade improvement.

B supports the study pattern. I can agrue that students changed study habit when they went on this nutricitional program and hence no grade imrovement.
_________________

If you like my post, consider giving me some KUDOS !!!!! Like you I need them

Kudos [?]: 101 [1], given: 9

Joined: 31 Dec 1969

Kudos [?]: [1], given:

Location: Russian Federation
GMAT 3: 740 Q40 V50
GMAT 4: 700 Q48 V38
GMAT 5: 710 Q45 V41
GMAT 6: 680 Q47 V36
GMAT 9: 740 Q49 V42
GMAT 11: 500 Q47 V33
GMAT 14: 760 Q49 V44
WE: Supply Chain Management (Energy and Utilities)

### Show Tags

28 Jul 2010, 10:31
1
KUDOS
TallJTinChina wrote:
These are the kind of questions that make me hate multiple guess exams.

None of the choices are good. I choose F.

F) The control group (no special diet) had higher average grades before the study was conducted.

+1

Kudos [?]: [1], given:

Senior Manager
Joined: 05 Jul 2010
Posts: 353

Kudos [?]: 52 [1], given: 17

### Show Tags

01 Aug 2011, 08:19
1
KUDOS
This is a kick-ass question. I selected D based on the 1st rationale that somebody added, but after reading more I can see how E might be the right choice. Although, when in doubt I tend to leave the choices that need very very strong inference to strengthen the argument. But this question stem is very tricky.

I try to keep it simple by thinking stem: Strengthen ConclusionX = Weaken conclusion. But here the Stem is not even referring to the conclusion but the validity of the sample used and hence the accuracy of the study. Too much mumbo jumbo in the question stem.

This question does NOT fall under any standard CR question, rather it wants us to weaken a part of the premise.

Anyways, if I get such complex question in my test, I will be happy to get it wrong as I will already be in my course for a good verbal score

Kudos [?]: 52 [1], given: 17

Manhattan Prep Instructor
Joined: 04 Dec 2015
Posts: 402

Kudos [?]: 239 [1], given: 56

GMAT 1: 790 Q51 V49
GRE 1: 340 Q170 V170
Re: A recent study of college students shows that, contrary to [#permalink]

### Show Tags

22 Aug 2016, 15:08
1
KUDOS
Expert's post
Part of what makes this an unfair question is the phrasing of the sentence "Sixty students, half of whom were given a nutritionally balanced diet, had grades no higher than did those students who were not placed on the diet plan." Is it saying that there was a group of 60 students who all volunteered for the study, half of the volunteers received a nutritious diet, but all 60 (regardless of diet) had higher grades than students who weren't involved in the study? Or is it saying that of the 60 students who volunteered for the study, the half who were given a nutritious diet had the same grades as the half who didn't?

Even though the first reading seems illogical, it's what the sentence is saying, grammatically! But if the second reading is what's intended, I can understand why (E) isn't correct. If every student who volunteered for the study was in the first or second year, including both the students who were given a nutritious diet and the students who weren't, then the result could still be valid. It's not extensible to the entire college population (maybe, for some weird reason, nutrition only affects older students and not younger ones?) but it's still valid, because it's comparing two comparable groups.

(D) is certainly wrong by GMAT standards too, though. The GMAT doesn't accept answers that require that you assume that one group of people is the same as another group of people, without proving it. The argument would have to show that high school students are physiologically the same as college students, for (D) to stand a chance.
_________________

Chelsey Cooley | Manhattan Prep Instructor | Seattle and Online

My upcoming GMAT trial classes | GMAT blog archive

Kudos [?]: 239 [1], given: 56

Manager
Joined: 04 Jun 2008
Posts: 155

Kudos [?]: 84 [0], given: 0

### Show Tags

07 Jul 2008, 06:22
A recent study of college students shows that, contrary to predicted results, special nutritional planning does not positively affect students’ grades. Sixty students, half of whom were given a nutritionally balanced diet, had grades no higher than did those students who were not placed on the diet plan.

Which of the following, if true, is most useful in determining the accuracy of the study described above?

i) Performance of business executives was shown to improve drastically after major alterations were made in their diets. irrelevant
ii)Honors students, after altering their diets, maintained that they did not change their study habits. Not talking about study habits.Also, Unchanged study habits may not guarantee same high grades.
iii)Students who participated in various fitness regimens found that their grades improved appreciably after they altered their exercise habits. irrelevant
iv) High school students who previously had low grades found that after they altered their diets, their grades improved dramatically. tells us precisely whether argument's conclusion is accurate or not.
v) All of the college students who volunteered for the study were either in their first or second year of college.
irrelevant

IMO D

Kudos [?]: 84 [0], given: 0

Manager
Joined: 04 Jun 2008
Posts: 155

Kudos [?]: 84 [0], given: 0

### Show Tags

07 Jul 2008, 07:08
gixxer1000 wrote:
chan4312 wrote:
A recent study of college students shows that, contrary to predicted results, special nutritional planning does not positively affect students’ grades. Sixty students, half of whom were given a nutritionally balanced diet, had grades no higher than did those students who were not placed on the diet plan.

Which of the following, if true, is most useful in determining the accuracy of the study described above?

i) Performance of business executives was shown to improve drastically after major alterations were made in their diets. irrelevant
ii)Honors students, after altering their diets, maintained that they did not change their study habits. Not talking about study habits.Also, Unchanged study habits may not guarantee same high grades.
iii)Students who participated in various fitness regimens found that their grades improved appreciably after they altered their exercise habits. irrelevant
iv) High school students who previously had low grades found that after they altered their diets, their grades improved dramatically. tells us precisely whether argument's conclusion is accurate or not.
v) All of the college students who volunteered for the study were either in their first or second year of college.
irrelevant

IMO D

How does that affect the accuracy of this test?

If I do a test of college students. And I ask you to comment on the accuracy of my test on college students and you tell me you did a test on high school students and got different results. How does that affect the ACCURACY of my test? Wouldn't you have to focus on my methods to comment on the accuracy of my test?

To me we are only concerned with the accuracy of the study and not the results.

I can not agree with you.
we are talking about how students respond to planned special nutritional diet.
Does it matter if the student is a college student or high scholl student.whether student is 15 year old or 35 year old. unless people respond differently for the same diet.argument does not say so..so we can not predict. I do not think it matters. our input is diet and our output is grades. if this holds true/false determines whether study is accurate/inaccurate.

Kudos [?]: 84 [0], given: 0

Director
Joined: 26 Jul 2007
Posts: 535

Kudos [?]: 180 [0], given: 0

Schools: Stern, McCombs, Marshall, Wharton

### Show Tags

07 Jul 2008, 07:19
chan4312 wrote:
gixxer1000 wrote:
chan4312 wrote:
A recent study of college students shows that, contrary to predicted results, special nutritional planning does not positively affect students’ grades. Sixty students, half of whom were given a nutritionally balanced diet, had grades no higher than did those students who were not placed on the diet plan.

Which of the following, if true, is most useful in determining the accuracy of the study described above?

i) Performance of business executives was shown to improve drastically after major alterations were made in their diets. irrelevant
ii)Honors students, after altering their diets, maintained that they did not change their study habits. Not talking about study habits.Also, Unchanged study habits may not guarantee same high grades.
iii)Students who participated in various fitness regimens found that their grades improved appreciably after they altered their exercise habits. irrelevant
iv) High school students who previously had low grades found that after they altered their diets, their grades improved dramatically. tells us precisely whether argument's conclusion is accurate or not.
v) All of the college students who volunteered for the study were either in their first or second year of college.
irrelevant

IMO D

How does that affect the accuracy of this test?

If I do a test of college students. And I ask you to comment on the accuracy of my test on college students and you tell me you did a test on high school students and got different results. How does that affect the ACCURACY of my test? Wouldn't you have to focus on my methods to comment on the accuracy of my test?

To me we are only concerned with the accuracy of the study and not the results.

I can not agree with you.
we are talking about how students respond to planned special nutritional diet.
Does it matter if the student is a college student or high scholl student.whether student is 15 year old or 35 year old. unless people respond differently for the same diet.argument does not say so..so we can not predict. I do not think it matters. our input is diet and our output is grades. if this holds true/false determines whether study is accurate/inaccurate.

We are talking about how sixty college students respond to a planned special nutrition diet. We need information to help determine the accuracy of the study. Contradicting results from another study does not affect the accuracy of this studies results. We are looking for answers that shows that the sixty college students chosen are a good or bad sample. Or some other reason to show that the study was accurate or inaccurate.

Kudos [?]: 180 [0], given: 0

Senior Manager
Joined: 25 Nov 2006
Posts: 264

Kudos [?]: 38 [0], given: 0

### Show Tags

07 Jul 2008, 08:35
It's a tough fight between A and D for me.
Since Conclusion is not a generic statement that diets help in performance but specific to students, I am more inclined to opt for D.

E is clearly out, it really does not matter who took the test as long as they were students. Facts clearly mention that it is just students who took the test.

Kudos [?]: 38 [0], given: 0

Director
Joined: 26 Jul 2007
Posts: 535

Kudos [?]: 180 [0], given: 0

Schools: Stern, McCombs, Marshall, Wharton

### Show Tags

07 Jul 2008, 08:49
Ashwin_Mohan wrote:
It's a tough fight between A and D for me.
Since Conclusion is not a generic statement that diets help in performance but specific to students, I am more inclined to opt for D.

E is clearly out, it really does not matter who took the test as long as they were students. Facts clearly mention that it is just students who took the test.

So if you chose 30 college seniors with straignt A's and 30 college freshmen with all D's that wouldn't affect the ACCURACY of the test results.

I fail to see how outside test results affect the accuracy this test results. Can someone explain?

Kudos [?]: 180 [0], given: 0

VP
Joined: 05 Jul 2008
Posts: 1402

Kudos [?]: 437 [0], given: 1

### Show Tags

07 Jul 2008, 08:50
gixxer1000,

If you look at the Q again, it does not say how does it effect the accuracy of the test?

It says which one will be most helpful in determining the accuracy of the test?

Kudos [?]: 437 [0], given: 1

Director
Joined: 26 Jul 2007
Posts: 535

Kudos [?]: 180 [0], given: 0

Schools: Stern, McCombs, Marshall, Wharton

### Show Tags

07 Jul 2008, 09:38
icandy wrote:
gixxer1000,

If you look at the Q again, it does not say how does it effect the accuracy of the test?

It says which one will be most helpful in determining the accuracy of the test?

I understand that. We need to choose the answer that most helps us determine if the test is or is not accurate. So to determine if the test is accurate we need to look at the methods of the test. How it was conducted, who was tested, etc. A, B, C, and D all deal with factors other than the test in question. How would these outside factors help us to determine the accuracy of this test.

Kudos [?]: 180 [0], given: 0

VP
Joined: 03 Apr 2007
Posts: 1340

Kudos [?]: 831 [0], given: 10

### Show Tags

07 Jul 2008, 09:58
gixxer1000 wrote:
icandy wrote:
gixxer1000,

If you look at the Q again, it does not say how does it effect the accuracy of the test?

It says which one will be most helpful in determining the accuracy of the test?

I understand that. We need to choose the answer that most helps us determine if the test is or is not accurate. So to determine if the test is accurate we need to look at the methods of the test. How it was conducted, who was tested, etc. A, B, C, and D all deal with factors other than the test in question. How would these outside factors help us to determine the accuracy of this test.

Conclusion: special nutritional planning does not positively affect students’ grades.
Evidence:Sixty students, half of whom were given a nutritionally balanced diet, had grades no higher than did those students who were not placed on the diet plan.

The evidence here is weak becuase it provides no details about the student's grade before and after the intake of special diet.Only D brings in information to say students with previously lower grades performed well after they started takin in special diet and refute the conclusion that special diet donot affect student's growth. This answer choice can used to measure the accuracy of this conclusion made in the argument.

Kudos [?]: 831 [0], given: 10

Manager
Joined: 03 Jun 2008
Posts: 133

Kudos [?]: 45 [0], given: 0

Schools: ISB, Tuck, Michigan (Ross), Darden, MBS

### Show Tags

07 Jul 2008, 10:03
bhatiasanjay01 wrote:
A recent study of college students shows that, contrary to predicted results, special nutritional planning does not positively affect students’ grades. Sixty students, half of whom were given a nutritionally balanced diet, had grades no higher than did those students who were not placed on the diet plan.

Which of the following, if true, is most useful in determining the accuracy of the study described above?

i) Performance of business executives was shown to improve drastically after major alterations were made in their diets.
ii)Honors students, after altering their diets, maintained that they did not change their study habits.
iii)Students who participated in various fitness regimens found that their grades improved appreciably after they altered their exercise habits.
iv) High school students who previously had low grades found that after they altered their diets, their grades improved dramatically.
v) All of the college students who volunteered for the study were either in their first or second year of college.

I marked the answer at ii), because if no changes were made to the study habits then we can conclude that there was no effect of study habits on the study, hence effect of diet can be correctly determined (Whether it had some effect or not). But this answer is wrong . Can anybody explain the correct answer).

Option E points towards the homogeneity of the sample.

E for me too.

However I feel such a survey cannot be conclusive. A better prepared survey would measure the performance of the same student over time.. when he is on an ordinary diet vs when he is on a planned nutritional diet.
_________________

-----------------------------------------------------------
'It's not the ride, it's the rider'

Kudos [?]: 45 [0], given: 0

Re: CR: Nutrition Study   [#permalink] 07 Jul 2008, 10:03

Go to page    1   2   3   4   5    Next  [ 81 posts ]

Display posts from previous: Sort by