A medical journal used a questionnaire survey to determine whether

Choice (C) specifically tells us that 62% of the ENTIRE POTENTIAL READERSHIP would like to have a format change. Without choice (C), it is possible that only a very small portion of the entire readership actually wants a format change. Thus, even if MOST of the readers who support a format change like this change, that would still only represent a tiny portion of overall readership.

In other words, say that we somehow knew that MOST people who support a format change actually responded to the survey. Even knowing that information, the survey results would still be meaningless because we do not know what percent of readers want a format change at all.

However, with choice (C), we now know that MOST readers would like a format change. Thus, if MOST readers who support a format change actually responded to the survey, then the survey would be evidence that the format change will be a success. True, choice (C) does not PROVE that the change will be a success. It is still possible that most readers who supported a change did not respond to the survey. But choice (C) eliminates a possibility (described in the last paragraph) that would weaken the conclusion. Thus, choice (C) strengthens the argument. If most readers favored a change, it is MORE likely that a greater number responded to the survey and thus MORE likely that the plan will succeed.

As for choice (A), we still don't know what percentage of readers received questionnaires. If the survey was only sent to a very small portion of readers, it wouldn't matter that all or most of them returned the survey. It would still be unlikely that the survey accurately represented readers in general.

Choice (A) also leaves the possibility that all or most of the readers surveyed supported a format change. And if that only represents a tiny fraction of OVERALL readership, then the survey at best tells us that an even tinier fraction support this specific change. Choice (C) eliminates this possibility, so it is a better answer.

I hope that helps!
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(A) Of the readers who received questionnires, 90 percent returned them.
(C) The percentage of surveyed readers who like the format change was almost the same as the percentage of the entire potential readership who would like format change.
(E) Ninety percent of the readers who were dissatisfied with the old format and only 50 percent of the readers who like the old format returned their questionnaires.

62% like the old format out of those who returned the questionnaire.
But what if the no. of people who have returned the questionnaire is quite less. Lets only out of 100 people, only 7 people have responded so out of that 5 like the format, 2 not. what about rest 93 cases. we don't about that. It can skew our data.

A) 90% returned so
90* 62/100 = 55
so yes, people liked the new format. But still is it true representative of entire population. We don't know.

C ADDRESS THIS ISSUE.
(C) The percentage of surveyed readers who like the format change was almost the same as the percentage of the entire potential readership who would like format change.

The percentage of surveyed readers who like the format change = we don't know if it 62 or less than 62 based on no. of readers responded.
so again there is a possibility that only 7% of potential readership who would like format change.

Pl help with this ques
I don't like both A, C and also I don't know why E wrong?

+ C.

We need to give the evidence that the journal's decision will have the desired effect? i.e readership would increase.

This option talks about the potential readers and it says the percentage of surveyed readers who like the format change was almost the same as the percentage of the entire potential readership
So if they the potential readers voted for this change their likelihood of reading the journal would be high once the changes are incorporated.

How can we rely on percentages, considering the number of people might actually vary.

Thank you very much this is useful

the surveyed readers truly correspond to all readers. So since 62% reacts positively, it means 62% of all readers react positively, that's why I think C is correct ...
but A is a very powerful contender

thanks

I go with c. Since percentage of reader's surveyed resembles general population this option is valid. But what's wrong with A and E?

Sent from my XT1562 using GMAT Club Forum mobile app

For A : "Of the readers who received. .." means these people are already readers of the journal. If we want to increase readership ie induce people who did not read the journal before to start reading it, we should not concern ourselves with those who are already readers.
I would think the same about option E.
One reason why C is correct is because it clearly states POTENTIAL readership.

Hope this helps.

i went with A and here follows my line of reasoning.
A-Lets assume there were 1000 readers/ readers who received the questionnaire. 900 returned and out of which 62% supported then approximately 558 persons supported- i felt this is better
B- other journals - None of my business
C- i rejected this option bec we know nothing about the people who would have liked the format change but would not have returned the questionnaire. lets say 1000 readers surveyed out of which 200 only returned the questionnaire. out of which only 112 supported the change. as a result only 11.2 % of 1000 readers supported the change. we have no concrete information about the rest 800 readers whether they liked or disliked the change. So how can we assume the choices of remaining 800 persons. - does not strengthen
D- Monetary aspect- not our concern
E- lets say 1000 readers surveyed. 400 disliked and 600 liked the old format. 90% of disliked=> 360 and 50% of liked=> 300. total returned the questionnaire = 660 out of which only 62% supported the change making it 409 people supported the change=>41% of the readers surveyed would like the change. - Does not strengthen.


Of all the options A had the highest probability as a strengthener. so i went for A. Requesting experts to correct me where i went wrong.

C..The percentage of surveyed readers who like the format change was almost the same as the percentage of the entire potential readership who would like format change. Not clear about C. What if the % of surveyed readers was only 1% and the % of potential pool of readers was say 2% , those % would amount to few people that like that fomat change thus making that decision ill founded.
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A medical journal used a questionnaire survey to determine whether a particular change in its format would increase its readership. Sixty-two percent of those who returned the questionnaire supported that change. On the basis of this outcome, the decision was made to introduce the new format.

Which one of the following, if it were determined to be true, would provide the best evidence that the journal's decision will have the desired effect?

(A) Of the readers who received questionnires, 90 percent returned them. -We don't know that how many people received questionnaire; thus we can't say that 90% is a big number or not.
(B) Other journals have based format changes on survey results. -We are not worried about other journals
(C) The percentage of surveyed readers who like the format change was almost the same as the percentage of the entire potential readership who would like format change. -Correct. This states that 62% would actually love the change
(D) It was determined that the new format would be less costly than the old format. -Cost? Out of scope
(E) Ninety percent of the readers who were dissatisfied with the old format and only 50 percent of the readers who like the old format returned their questionnaires. -Irrelevant

A medical journal used a questionnaire survey to determine whether a particular change in its format would increase its readership. Sixty-two percent of those who returned the questionnaire supported that change. On the basis of this outcome, the decision was made to introduce the new format.

Pre-thinking -- was the sample representative of total population in general ? What if it was only sent to a hundred random magazine readers, out of a million total? Then there would be a good chance that it's not representative.

Which one of the following, if it were determined to be true, would provide the best evidence that the journal's decision will have the desired effect?

(A) Of the readers who received questionnires, 90 percent returned them. -- Incorrect - (A) is a worse answer because it leaves open the much more important issue of whether the surveyed readers are representative of the readers in general. Okay, maybe 90 percent returned the questionnaire .... but 90 percent of how many? If only ten people got it, then we haven't necessarily learned much about the readership. We need to know whether the views of the surveyed people correspond to the views of the overall group.
(B) Other journals have based format changes on survey results. -- Irrelevant
(C) The percentage of surveyed readers who like the format change was almost the same as the percentage of the entire potential readership who would like format change. -- strengthens the proposal by establishing that the surveyed group is representative of the magazine's readership in general. I think "surveyed" should be interpreted to refer to the people who returned the questionnaire. If a questionnaire shows up in my mailbox and I never open the envelope, we can't say that I have been surveyed. So we don't need to worry about whether the people who sent the thing back are representative; answer (C) is actually referring to them.
(D) It was determined that the new format would be less costly than the old format. -- Irrelevant -- cost is not an issue here
(E) Ninety percent of the readers who were dissatisfied with the old format and only 50 percent of the readers who like the old format returned their questionnaires. -- this is mild weakner as it says that survey was a little flawed.

Answer C
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In this choice: The percentage of surveyed readers who like the format change was almost the same as the percentage of the entire potential readership who would like format change-->We don't know the the actual number of surveyed readers who liked the format,we only know the percentage of those who returned the survey.
How can we compare this with the actual potential readers.

I chose 'A' and got this wrong. I went through explanations and I got why C is correct answer. However, since I found no answer explanation exactly pointed out, what I got, thought of giving my two cents here.


Premise: A medical journal used a questionnaire survey.
Premise:Survey was to determine whether a particular change in its format would increase its readership.
Premise: Sixty-two percent of those who returned the questionnaire supported that change.
Conclusion:On the basis of this outcome, the decision was made to introduce the new format.

Which one of the following, if it were determined to be true, would provide the best evidence that the journal's decision will have the desired effect?

So we need to provide support i.e. we need to find a strengthener


(A) Of the readers who received questionnires, 90 percent returned them. <== But what percent excatly received is no where mentioned in premise. It may strengthen, may NOT strengthen. Eliminate.
(B) Other journals have based format changes on survey results. <== We are NOT concerned about other journals format changes. Moreover, it still NOT show any relevenace with percentage surveyed and responded and positive responses. Eliminate.
(C) The percentage of surveyed readers who like the format change was almost the same as the percentage of the entire potential readership who would like format change. <== May be. but not sure why should we eliminate. Let's keep this.
(D) It was determined that the new format would be less costly than the old format. <== But not sure, if it will help in desired effect - readership increase . Eliminate.
(E) Ninety percent of the readers who were dissatisfied with the old format and only 50 percent of the readers who like the old format returned their questionnaires. <== This gives percentages of people in both categories that responded to survey but fails to classify, how many (or proportion) in total were in favor of change and how many in total wanted old format only.Eliminate

Since we are remained with only one option - option C is the final answer.
Moreover the option talks about total percentages in favor of change . And since it says percentage 'surveyed' means people who responded- see the highlighted part - hence its the answer.
(C) The percentage of surveyed readers who like the format change was almost the same as the percentage of the entire potential readership who would like format change.

Press Kudos, if my efforts have helped in any way and to any extent.
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The problem with A and E is that we're only provided with percentages -- we don't know the number of people in each group.

The goal is to increase readership.

Choice A tells us that of the readers who received questionnaires, 90 percent returned them. But do we know the number of people that received questionnaires? What if this population was only 1% of its readers? A is out.

Choice E tells us that ninety percent of the readers who were dissatisfied with the old format and only 50 percent of the readers who like the old format returned their questionnaires. Again, we don't know the number of people in each group. What if only 10 readers were dissatisfied with the old format and 1,000 readers were satisfied? We could end up losing readers!

Choice C is iron clad -- the 62% is representative of the entire potential readership. C is the answer.
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A medical journal used a questionnaire survey to determine whether a particular change in its format would increase its readership. Sixty-two percent of those who returned the questionnaire supported that change. On the basis of this outcome, the decision was made to introduce the new format.

The magazine sent a survey to its readers.
Of those who answered back (survey participants), 62% supported the change.

Magazine decided to implement the change.

So based on the opinion of a sample, the magazine assumed that the opinion among the population will be the same and hence decided to implement the change. We need to support this line of thinking which means we need to give some data that supports that the sample does represent the population.

(A) Of the readers who received questionnires, 90 percent returned them.

This option tells us that 90% of the magazine's readership was the sample size i.e. 90% people participated in the survey. Now think about this - does it matter whether 90% participates or 80% participate or 40% participated? The number of people that participated are our sample. We don't know whether the absolute number is large or small. If the magazine's readership has very few people, 90% may be a small sample size. If the magazine has a large readership base, 40% may be a large enough sample size too.
So this option doesn't really provide any support to the authenticity of the survey result.

(B) Other journals have based format changes on survey results.

Irrelevant. We don't know whether the journals were similar and whether their decisions turned out to be suitable.

(C) The percentage of surveyed readers who like the format change was almost the same as the percentage of the entire potential readership who would like format change.

Correct. This says that the sample was an accurate representation of the entire population. If that is the case, then we can expect 62% of the entire potential readership to like the change. It certainly sounds good for the plan.

(D) It was determined that the new format would be less costly than the old format.

Cost is not being discussed here. We are discussing increase in readership.

(E) Ninety percent of the readers who were dissatisfied with the old format and only 50 percent of the readers who like the old format returned their questionnaires.

This weakens the result of the survey and is hence not the answer.

Assuming 100 people responded to the survey, 62 liked the new format while 38 liked the old format.
This option (E) tells us that the 38 people who liked the old format were only 50% of the total who liked the old format. So actually 76 people liked the old format.
Also it tells us that the 62 people who liked the new format were 90% of all total who liked the new format so about 69 people liked the new format.

Hence, in reality more people liked the old format better and the change may not be good for the magazine. Just that fewer people who liked the old format responded.

Answer (C)

A medical journal used a questionnaire survey to determine whether a particular change in its format would increase its readership. Sixty-two percent of those who returned the questionnaire supported that change. On the basis of this outcome, the decision was made to introduce the new format.

Which one of the following, if it were determined to be true, would provide the best evidence that the journal's decision will have the desired effect?

(A) Of the readers who received questionnires, 90 percent returned them. - WRONG. What percentage of readers received the questionnaires?? Too open a pool to consider the option as an answer.
(B) Other journals have based format changes on survey results. - WRONG. Irrelevant.
(C) The percentage of surveyed readers who like the format change was almost the same as the percentage of the entire potential readership who would like format change. - CORRECT. Proportionality established and thus this one supports.
(D) It was determined that the new format would be less costly than the old format. - WRONG. Irrelevant.
(E) Ninety percent of the readers who were dissatisfied with the old format and only 50 percent of the readers who like the old format returned their questionnaires. - WRONG. What is the percentage of those who were dissatisfied to actual readers? Again similar question can be raised about the 50% who liked. It presents so many possibilities(in support and against both) that this would be wrong answer.

Answer C.
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For option C, Could you please explain why we do not consider the possibility that only say 20% of the survey takers actually returned the survey? Does that not mean that we do not know what the remaining 80% voted for?.