In a recent poll, 71% of respondents reported that they cast votes in

Question

In a recent poll, 71% of respondents reported that they cast votes in the most recent national election. Voting records show, however, that only 60% of eligible voters actually voted in that election.

Which of the following pieces of evidence, if true, would provide the best explanation for the apparent discrepancy?

(A) The margin of error for the survey was plus or minus five three percentage points.

(B) Fifteen percent of the survey's respondents were living overseas at the time of the election.

(C) Prior research has shown that that people who actually do vote are also more likely to respond to polls than those who do not vote.

(D) Many people who intend to vote are prevented from doing so by last-minute conflicts on election day or other complications.

(E) Some people confused the national election with other recent elections when responding to the poll.

piyushksharma · Accepted Answer

I found this explanation at manhattan forum.Please let me know if this one is correct or not.

Let me break this up....
suppose in a area 1000 ppl lived who were eligible to vote....
poll result shows 60% success... which means 600 ppl actually voted....

Now, the survey result-
71% said 'yes'.... the survey may have covered only 500 ppl or lets say the survey was responded by only 500 ppl who were excited about the election, though some of them would not have been able to vote...rest 500(including some of the ppl who actually voted) did not bother to answer the survey....

out of the 500 survey respondents, the number of ppl actually voted would be 355, rest would not have voted or were not eligible to vote...The agency which conducted the survey speculated and presented to the public that 71% voting has been done...

Hence, choice C fits the best...

DexDee · Answer

I pick C as well.

We are looking for a legitimate reason as to why the survey results are skewed to show higher percentage of voting. This can happen if the sample space (for the poll) itself is corrupted with a larger than proportionate number of people who have voted.

C says that people who have voted are more likely to join such a poll than those who have not. Settles our problem!

tuanquang269 · Answer

Only choice C is correct, it states that the people who are eligible for voting are play 60/71% in poll. 11% remains are the ineligible people to vote election.

rustypolymath · Answer

When there's a discrepancy, it is always a problem of the comparability of one category to another. In this case, the sample that was polled must not have been representative of the general population. If people who did vote were more likely to answer the survey period, then that would drive the average up in the survey.

BDSunDevil · Answer

OA is C: according to the below link. https://www.manhattangmat.com/forums/mgm ... t6511.html I don't understand the logic. Whats wrong with E. At least C is not the best choice.

holidevil · Answer

I put the following points to say that E is wrong:
1. It talks of  some peope . It is difficult to assume how many does some consist of? They can be whole or part of the sample.
2. If some people who were confused with the elections and who didn't vote, then the result of respondent could come down. But the result has gone up. It ignores this possibility.

C is correct in the following respects:
1. It talks of people who voted and participated in the vote.
2. It talks of such people as  more likely  to participate, instead of a vague term of some.

dheeraj24 · Answer

First of all thanks aalokk, for posting such a superb and tricky question.

This question is regarding how we analyze groups and sub-groups.

We were told
p1 : 71% of respondents reported that they cast votes in the most recent national election
p2: only 60% of eligible voters actually voted in that election.

We need to explain the discrpeancy
Let us take an example for this. Assume in a village there are 1000 members.

The poll surveyed 500 among them(sub -group) .From this group 71%(355 out of 500) of respondents reported that they cast votes.

Here also focus on the term eligible voters. Out of 1000 members , some are eligible and some are not eligible.

Out of 1000 members , 600 People voted .

Hope this helps

veergmat · Answer

I am unable to understand what the Option C is trying to explain. Can somebody help ?

chetan2u · Answer

hi  veerdonjuan ,
choice C is (C) Prior research has shown that people who actually do vote are also more likely to respond to polls than those who do not vote...
we have two different sets numbers..
1) in a survey conducted, 71% say that they cast votes. we do not know what constitutes of this group .. who all parcipated..
2) actual % is 60%..

now what C does is it tries to cover the gap by telling us that people who did not vote are less likely to respond to the survey...
since in the survey , the number of person not voted have not reponded, this has increased the % of people had voted..
hope it helped..

chetan2u · Answer

Hi,
 The first mistake You have done is TIMEFRAME when this survey was done..
It was done after the elections and NOT before..

71% say they had casted the vote, while ONLY 60% of those eligible had voted..
Why did more number of people say that they had casted the vote

lets see the choices CORRECT and D 
C) Prior research has shown that people who actually do vote are also more likely to respond to polls than those who do not vote.
 It says that people who voted actually become a part of this survey than people who do not vote..
Therefore if 200 people were eligible and 150 voted and 50 did not vote.. thus 75% voted..
But in survey 80% of those who voted took part as compared to 60% of those who did not vote..
so total surveyed= 0.8 * 150 +0.6 * 50 = 150..
people who said they voted = 0.8 * 150 = 120..
so % = 120/150 = 80%....
so 80% in survey agreed on voting whereas only 75% of total had voted..

D) Some people who intent to do vote are prevented from doing so by last-minute conflicts on election day or other complications.
 These talks of people who had intention of voting BUt could not vote..
they are as it is not part of this survey in Q..

optmistic2016 · Answer

chetan2u Thanks for the explanation - now option C makes sense but this is a very tricky question - what is the difficulty level?

Regarding option D, you mentioned about timeframe, but this is not explicitly mentioned that survey was done before the election or after?

'In a recent poll, 71% of respondents reported that they cast votes in the most recent national election." -> it doesnt state that survey was done prior or after - it states - recent survey, recent national elections.

Please clarify which point am I missing?

chetan2u · Answer

Hi,
the sentence reads
'In a recent poll, 71% of respondents reported that they cast votes  in the most recent national election."

If it was prior to elections, the sentence would be
'In a recent poll, 71% of respondents reported that they  would  cast votes in the most recent national election."

Hope it helps

TeamGMATIFY · Answer

60% of eligible voters voted -> this means that, of all of the people who were registered / allowed to vote, 60% of them voted.

The 71% refers to people who answered the poll.
 
So we are talking about two different groups here. The poll surveyed a particular set of people , some of whom voted and some of whom did not vote. Some of the people polled may not even have been eligible to vote.

Now Lets take the case that we have eligible voters as say 1000 - that means 600 of them voted.
The respondents can be the set of people who were eligible to vote and some people who were not eligible to vote - it could be figure more than 1000 or a figure less than 1000.

If the figure is more than 1000 then 71% of respondents would mean a figure of more than 710 but that is more than even the number of people who voted.
That would mean that the number of respondents should be a figure fewer than 1000 - and when is that possible - Option choice C is right on the mark when it says that the people who voted are more likely to be respondents i.e if more people who actually voted participated in the respondent poll and fewer people who did not vote were part of the survey.

Choice D talks about intention before the election but we know that the poll happened after the people actually voted - and hence it does not help us.

Choice E is a confusing answer but there are a few things that come to mind when we thing of choice E as a potential answer
- if some people actually got confused then the figure of respondents can go either way - more than 60% or less than 60%. We should have to make a few additional assumptions while choosing the answer. 
Choice C is much better in this regard and hence is a better answer but for sure choice E does cause a lot of confusion in the head.

Hope this helps !!!

TeamGMATIFY · Answer

60% of eligible voters voted -> this means that, of all of the people who were registered / allowed to vote, 60% of them voted.

The 71% refers to people who answered the poll.

So we are talking about two different groups here. The poll surveyed a particular set of people , some of whom voted and some of whom did not vote. Some of the people polled may not even have been eligible to vote.

Now Lets take the case that we have eligible voters as say 1000 - that means 600 of them voted.
The respondents can be the set of people who were eligible to vote and some people who were not eligible to vote - it could be figure more than 1000 or a figure less than 1000.

If the figure is more than 1000 then 71% of respondents would mean a figure of more than 710 but that is more than even the number of people who voted.
That would mean that the number of respondents should be a figure fewer than 1000 - and when is that possible - Option choice C is right on the mark when it says that the people who voted are more likely to be respondents i.e if more people who actually voted participated in the respondent poll and fewer people who did not vote were part of the survey.

Choice D talks about intention before the election but we know that the poll happened after the people actually voted - and hence it does not help us.

Choice E is a confusing answer but there are a few things that come to mind when we thing of choice E as a potential answer
- if some people actually got confused then the figure of respondents can go either way - more than 60% or less than 60%. We should have to make a few additional assumptions while choosing the answer.

Choice C is much better in this regard and hence is a better answer but for sure choice E does cause a lot of confusion in the head.

Hope this helps !!!

BillyZ · Answer

In a recent poll, 71% of respondents reported that they cast votes in the most recent national election. Voting records show, however, that only 60% of eligible voters actually voted in that election.

Which of the following pieces of evidence, if true, would provide the best explanation for the discrepancy?

A. The margin of error for the survey was plus or minus five percentage points.
( Margin of error, bingo! Excellent. So the real percentage could’ve been anywhere from…71% + 5% to 71% − 5%, which is still 66%. This doesn’t go far enough. Still, it’s about margin of error. I’m going to keep this one and come back to it later. )
B. Fifteen percent of the survey's respondents were living overseas at the time of the election.
( This percentage is larger than the 11% discrepancy mentioned in the argument. But what group are they talking about? Are these the people who did vote, or didn’t vote, or some mix of the two? And what does “living overseas” imply? This country might allow people to vote by absentee ballot. This doesn’t resolve anything. )
C. Prior research has shown that people who actually do vote are also more likely to respond to polls than those who do not vote. 
( What does that mean? Of the people who responded, more were likely to have been voters than is represented in the overall population. Oh, I see - the survey was skewed towards those voted. That's why 71% of that sub-group could have voted why only 60% of the overall population of eligible voters voted. That's better than A - I will get rid of A. )
D. Some people who intend to vote are prevented from doing so by last-minute conflicts on election day or other complications.
( I’m sure this is true in the real world. How does it affect this argument? The survey took place after the election; it asked people whether they had voted in the past. It doesn’t address what people intended to do before the election )
E. People are less likely to respond to a voting poll on the same day that they voted. 
( We have no idea when the poll was taken, so I can't do much with this. Even if the poll were done the same day as the election, this just highlights the discrepancy - it's even more puzzling now. I would expect the percentage of people who said they voted to be lower than the real percentage because those who didn't vote that day would be more likely to agree to participate in the poll. )

Source : Manhattan

longhaul123 · Answer

Can someone help me with this tricky question. Now this is how i evaluated the question.Lets say there are 1000 total members in a village , of which 60% = 600 have actually voted and that the poll results show that there are 71%=710 who have participated in the poll saying that they will vote in the recent election. Im not really understanding from here how do i evaluate the question . Kindly help.

arvind910619 · Answer

Hi longhaul123,

May be you have found the reason for C to be correct, but still i will explain here.

Here is the original question with all the options.

In a recent poll, 71% of respondents reported that they cast votes in the most recent national election. Voting records show, however, that only 60% of eligible voters actually voted in that election.

Which of the following pieces of evidence, if true, would provide the best explanation for the apparent discrepancy?

A. The margin of error for the survey was plus or minus five three percentage points.
B. Fifteen percent of the survey's respondents were living overseas at the time of the election.
C. Prior research has shown that that people who actually do vote are also more likely to respond to polls than those who do not vote.
D. Many people who intend to vote are prevented from doing so by last-minute conflicts on election day or other complications.
E. Some people confused the national election with other recent elections when responding to the poll.

This is paradox question. The paradox is that 71% of the folks took survey that they voted in the election and yet when election results came it only showed 60%. So this is the paradox.
Now to get this question right we should not assume that all those who participated in the survey voted. Survey is taken for some folks and from their response we extrapolate the finding to cover the entire population. To weaken such question we need to find some fault in sample space or in the process.

Now the paradox in this question can be resolved by saying that folks who vote are more likely to respond to surveys. This means that sample space would include more folks who voted thus skewing survey. 
So C is the only option that resolves the paradox.

Hope it helps

LeenaSai · Answer

Hi All ,

Here goes my explanation .

The question stem asks us to Resolve the discrepancy .

Let’s find out the discrepancies in the argument .

Poll - 71% Respondents — VOTED 
Voting records ( Actual). — 60%. — VOTED

Discrepancy of 11%

What could be the reason ? 
 1) Some technical or any kind of error in counting ( POLL)

2) Some technical or any kind of error in counting ( VOTING side )

These above those explanations should must address that 11% gap

Hence we can eliminate option (A : +- 5%)& (B: 15%)

3) No clear picture of the number of respondents, whereas the voting records actually counts the actual number of voters

Option (C) — satisfies what we just addresses above in point (3)

Let’s check option (D) : intention of voting ???

Option (E) : same day ???

Hence credited answer is (C)

Posted from my mobile device

Namangupta1997 · Answer

Hi  AndrewN

I am having a hard time understanding how C is correct. If people who ACTUALLY voted are more likely to be the respondents, there shouldn't be a discrepancy at all. If, for example, 60 people actually voted and they are also the ones who are more likely to be respondents, then how can this figure increase to 71? I am definitely missing something but I can't figure it out.

Also I had a hard time eliminating E. Is E eliminated because the "confusion" could have resulted the poll result to go either way?

In a recent poll, 71% of respondents reported that they cast votes in

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