What is the correct answer

[prarabh]

Advertisement: Do you want to be more energetic and physically fit? Take a daily supplement of Vita-Plus, a vitamin combination containing additional proprietary ingredients. Our Study using hundreds of volunteers show that just after 1 week of taking 2 capsules daily, participants report being more energetic and alert on average than the average level reported by national institute of health survey of all Americans

Which of the following will most strengthen the advertisements claim that vita-plus supplements make one more energetic and alert.

1) Those who voluntarily choose to take 2 capsules daily reported energy levels even greater than those who took only 2 capsules
2) The volunteers were randomly selected from all those who a newspaper advertisement and were willing to pay for the cost of Vita Plus capsules
3) At the beginning of the study, the volunteers' reports on alertness showed levels on average no different from the average level reported by National institute of health.
4) Some of the volunteers were given capsules that solely contained cellulose, an inert substance with no vitamins or health inducing substance. Those volunteers also reported increased levels of alertness and energy
5) Some of the volunteers were given capsules that solely contained cellulose, an inert substance with no vitamins or other health inducing substances. Those volunteers reported no increase in alertness or energy


I think the answer should be 3 but the official answer is 5. Can somebody explain why?

[lan0583]

my answer is like yours. I dont know why the answer is 5.

[800guy]

Advertisement: Do you want to be more energetic and physically fit? Take a daily supplement of Vita-Plus, a vitamin combination containing additional proprietary ingredients. Our Study using hundreds of volunteers show that just after 1 week of taking 2 capsules daily, participants report being more energetic and alert on average than the average level reported by national institute of health survey of all Americans

Which of the following will most strengthen the advertisements claim that vita-plus supplements make one more energetic and alert.

1) Those who voluntarily choose to take 2 capsules daily reported energy levels even greater than those who took only 2 capsules
2) The volunteers were randomly selected from all those who a newspaper advertisement and were willing to pay for the cost of Vita Plus capsules
3) At the beginning of the study, the volunteers' reports on alertness showed levels on average no different from the average level reported by National institute of health.
4) Some of the volunteers were given capsules that solely contained cellulose, an inert substance with no vitamins or health inducing substance. Those volunteers also reported increased levels of alertness and energy
5) Some of the volunteers were given capsules that solely contained cellulose, an inert substance with no vitamins or other health inducing substances. Those volunteers reported no increase in alertness or energy


I think the answer should be 3 but the official answer is 5. Can somebody explain why?

why i don't think it's 3: this answer talked about the volunteers alertness levels, but doesn't clarify anything about the effects of the capsules. also, doesn't clarify what kind of volunteers were selected. maybe these people in this group increased alertness because they were more prone to exercise and diet?

why the answer may be 5: focuses on how the capsules were distributed in a controlled scientfic manner: control and test subjects. implies that the volunteers that were selected represented the 'average' demographic, and that those who received placebo remained at average alterness.

[manishhemnani]

3) At the beginning of the study, the volunteers' reports on alertness showed levels on average no different from the average level reported by National institute of health.
4) Some of the volunteers were given capsules that solely contained cellulose, an inert substance with no vitamins or health inducing substance. Those volunteers also reported increased levels of alertness and energy
5) Some of the volunteers were given capsules that solely contained cellulose, an inert substance with no vitamins or other health inducing substances. Those volunteers reported no increase in alertness or energy



I still think the answer is 3. Here a small group of people is compared with overall population. We know that after taking suppliments, the group is doing better than population average, but we can't say that the group is representative sample of overall population. It is nowhere mentioned that after taking suppliments, the group is doing better than it was doing before consuming the suppliments.

[vinayjain]

A question for u 800guy what if the guyz who were given the vita capsules were the ones who excercised and dieted and thus their alertness leves increased.
then in tht case 5 doesent apply again.

[800guy]

A question for u 800guy what if the guyz who were given the vita capsules were the ones who excercised and dieted and thus their alertness leves increased.
then in tht case 5 doesent apply again.

if that were true, then you would be right that 5 wouldn't apply. but that detail isn't mentioned in the CR. i still like 5 the best because it sets up the experiment as having a test and a control...

this is a tough one!!

[aim-wsc]

same passage:
if you want to weaken the statement go for D
& for strengthen, E is the answer.

C seems convincing but what strengthens the Advertisers argument is the E.

[aficionado]

i can't see why E should be the answer. it is clearly out of scope. the answer has to be C., the question is not good, very ambiguous for Gmat levels.

[Stacey Koprince]

Can you tell us the source for this question? That might clear up the problem...

[Cybermusings]

It's 5 for sure!

[khanshainur]

Option 5 looks good. I'll go with 5.