The effect of voters previously stated preference regarding the issue

Question

https://gmatclub.com/forum/download/file.php?id=54314 The graph shows the effect of voters’ previously stated preference regarding the issue of working-time reduction on the probability of those voters’ actual choice being the same as that stated preference. For each party shown in the graph, less than 10% of that party's voters had a previously stated preference against the issue. Using the drop-down menus, fill in the blanks to make the most accurate statements based on the graph. Members of the GRAPH_1_PLACEHOLDER party are most apt to vote according to their previously stated preference regarding the issue of working-time reduction. Members of the GRAPH_2_PLACEHOLDER party are most apt to vote against the issue of working-time reduction if their previously stated preference regarding the issue of working-time reduction was also against. ID: 100375 66.jpg -

Bunuel · Accepted Answer

https://gmatclub.com/forum/download/file.php?id=54314 
 The graph shows the effect of voters’ previously stated preference regarding the issue of working-time reduction on the probability of those voters’ actual choice being the same as that stated preference. For each party shown in the graph, less than 10% of that party's voters had a previously stated preference against the issue. Using the drop-down menus, fill in the blanks to make the most accurate statements based on the graph.

Members of the _____________ party are most apt to vote according to their previously stated preference regarding the issue of working-time reduction.

Members of the _____________ party are most apt to vote against the issue of working-time reduction if their previously stated preference regarding the issue of working-time reduction was also against.

I will try to break down what the question is saying. However, note that to answer it correctly, you do not need to analyze it that deeply. DI questions often include extra information that you can skip or ignore.

Here is the setup. There is one issue being voted on: working time reduction (call it Issue A). Voters are grouped by political party: Delta, Sigma, Theta, and Zeta. “No Preference” is not a party. It is the group of voters who did not report a party affiliation.

Before the actual vote, each voter stated how they felt about Issue A. The x axis shows that stated preference on a scale: the far left is against, the far right is for, and the three tick marks in the middle are in between positions (for example: somewhat against, neutral, somewhat for). The exact labels are not shown, but the idea is “degree of support.”

The y axis is the probability that a voter’s actual vote matches what they previously stated. So if someone previously said “against,” the graph shows how likely they are to actually vote against. If someone previously said “for,” it shows how likely they are to actually vote for.

For example, look at the “against” end of the graph.
 
Zeta party voters are at about 0.70 there. That means that out of 100 voters affiliated with the Zeta party who previously said “against,” about 70 will actually vote against.
Delta party voters are at about 0.60 there. That means that out of 100 voters affiliated with the Delta party who previously said “against,” about 60 will actually vote against.

Now, about this line in the prompt:  For each party shown in the graph, less than 10% of that party’s voters had a previously stated preference against the issue.  This means the “against” group is small for every party (and also for the “No Preference” group). Keep that in mind, because it matters for the first drop down.

Now let’s move to the statements.

First drop down

What is it asking? “Most apt to vote according to their previously stated preference” means: which party’s voters are most likely, overall, to vote the same way they previously said they would, across the whole stated-preference scale (from against to for).

If you look across the five positions on the x axis, Delta’s line is the highest in four out of the five positions. The only place Delta is not the highest is at the far left (“against”), where Zeta is slightly higher.

This is exactly where the “ less than 10% ” detail matters. Someone might say, “But Zeta is higher at ‘against’.” True, but that point applies to a tiny minority of voters in every group. Since the question is asking who is most apt overall, you should not let a small edge in a tiny category outweigh being higher across the rest of the scale. Delta is the best overall.

So the first drop down is  Delta .

Second drop down

What is it asking? It is only talking about voters who previously said “against.” For that group, which party’s voters are most likely to actually vote against? So you only look at the far left “against” point on the graph and pick the party with the highest value there.

At that “against” point, Zeta is highest. So among voters who previously said “against,” Zeta voters are most likely to actually vote against.

So the second drop down is  Zeta .

Yes, the question is convoluted. It includes extra context that can distract you. The main skill is to focus on what each drop down is asking, and then read only the relevant part of the graph. Once you do that, it becomes straightforward.

Apt0810 · Answer

1)C,Delta will be chosen as most apt party since it's graph is rising towards the for area with the maximum value when compared with that of other parties.

2)D,Zeta are most apt for working against since they are having highest preference in that area,when looking at their past

Posted from my mobile device

mSKR · Answer

1. 
We need to find out most apt to vote according to previous stated preference
Sigma(~0.55)
Theta(0.60)
Delta(0.80)
Zeta(0.70)

So answer is C

2.most opt to vote against 
A. Sigma (0.55)
B. Theta (0.60)
C. Delta(0.60)
D. Zeta (0.70)

answer is D

bM22 · Answer

1. Members of the_____________party are most apt to vote according to their previously stated preference regarding the issue of working-time reduction.
What's asked is which teams previously stated reference/actual preference is the highest, => which party voted for in the previously stated reference and in the actual preference.
=> the probability for such team would be highest.
 Thus, we can infer from the graph, that the probability is maximum for Delta party (~ 0.8).

Answer C.

2. Members of the______________party are most apt to vote against the issue of working-time reduction if their previously stated preference regarding the issue of working-time reduction was also against.

The party which would be most apt to vote against, would be which has a higher probability in against and a lesser one in for.
From the graph,we can infer that the in case of against the  Zeta has the highest probability which goes from 0.70 to 0.45 , => Zeta's party members are most apt to vote against if their previous vote was also against.

Answer D.

Poojita · Answer

In IR questions that includes tables, charts or graphs, it's important to understand what the data "means." Based on the chart and the description next to it, here's what you should notice:

1) There are 5 political parties (including "no preference") and each has a line on the graph.
2) The lines represent the probability that a party members vote the SAME as their preference.
3) Preferences vary from "against" to "for" with 3 options "in the middle"
4) Individual data points will tell you the probability that one's "vote" matches one's "preference." For example, in the Delta party, if you look at the point that is farthest to the right, it tells you that about 80% of the Delta members whose preference is "for" the issue actually vote "for" the issue (and by deduction, about 20% vote in a way that differs from their preference).

The drop-down questions that follow ask you to look for "trending" data in the chart.

Q1 The party that is MOST apt to vote according to the preference (e.g. how they vote matches what they prefer). We'd be looking for an overall line that has a high percentage. Overall, the  Delta line  is above the other lines (except for one spot). THAT line is most apt to vote according to its preference.

Q2 The part that is MOST apt to vote AGAINST the policy IF the presence is to vote AGAINST. Here, we're looking for a specific point that has a high percent for the AGAINST option. The highest point is on the  Zeta line

Sajjad1994 · Answer

Official Explanation

In the graph, the vertical axis shows probabilities of voting in accordance with previously stated preferences, with greater probabilities represented higher on the axis. Thus, how apt the members of a party are to vote according to their previously stated preference is shown in the graph by how high the data points are that represent that party. The data points representing the Delta party are higher than the data points representing all the other parties except at the far left of the graph, where only the data point representing the Zeta party is higher. But because less than 10 percent of the Delta and Zeta parties' voters had a previously stated preference against the issue, this data has little effect on voters' overall likelihood to vote according to their previously stated preference. Therefore, members of the Delta party were most apt to vote according to their previously stated preference.

The correct answer is Delta.

In the graph, the heights of the data points above the word "against" indicate how likely the members of the various parties who previously stated they were against working-time reduction are to vote against it. Above the word "against," on the far left of the graph, the data point representing the Zeta party is higher than any of the points representing any of the other parties. Thus, members of the Zeta party are the most apt to vote against working-time reduction if they previously stated they were against it.

The correct answer is Zeta.

AndrewN · Answer

I spent a bit of time myself deciphering the first question, but then the task was easy. I will outline my thought process below.

The graph itself provides two pieces of information under the title "Working-Time Reduction":

probability of vote  
 issue preference (for/against)

We can see that there are four different parties, in addition to a group labeled "No Preference." The only part of the question stem that remains enigmatic is  previously stated preference . If I cannot find such information directly in the graph, I consult the paragraph above it. Here, the first line provides the key information:

Basically,  the y-axis indicates the probability that preference will match vote . (Remember, a probability can only go to 1.00, or 100 percent.) Now, since the question asks us to find the party  most apt  to vote according to its preference, we are simply looking to identify the group with the  strongest correlation on the y-axis . You can go through each data point if you prefer:

We can see that  Delta  has the highest overall correlation, not only by average, but also by individual point, so there can be little doubt that   the answer is (C)  .

Since we put in the legwork for the first question, the second one ought to be easy.

Boiled down, this question is looking for the group with the strongest correlation between against (preference) and against (vote).  The x-axis tells us that those most strongly against the issue, by preference, lie to the left , and if we look at that left-most data point for each group, we get the following:

Since the highest value is 0.70, the group we are looking for must be  Zeta , and   the answer is (D)  .

The phrasing of both questions sounds a bit formal or antiquated— apt to  is not in common usage, although it might appear in a newspaper story or a book.

Perhaps that sheds some light on the matter. Thank you for thinking to ask, and good luck with your studies.

- Andrew

tinbq · Answer

Hi  AndrewN ,

Would you please help to explain the graph? Take Delta Group for example, I don't understand about why we have 5 data points (perhaps time-series) and how to interpret those points (except for the first and last: 1. against 0.6, for 0.4; 5. against 0.2, for 0.8).

Thank you

AndrewN · Answer

Hello,  tinbq . If we look at the five values for Delta listed in the graph from left to right, we get, approximately, 0.60—0.69—0.73—0.78—0.81. According to the y-axis, these numbers correspond to the probability of a Delta party member casting a vote. But you should be asking yourself,  What kind of vote?  The x-axis tells us: a preference for or against an issue. Since there are five dashes on the x-axis, we can reasonably interpret the middle one as  neutral . The one on the far left is  against , so the one in between that and the center dash is likely  moderately against  or something similar. We can apply the same logic to the right side, in which the dashes would be  moderately for  and  for . Putting it all together, then, we can reasonably interpret the information for Delta party members as follows:

0.60—the probability of a given member who feels strongly  against  an issue casting a vote  against  that issue

0.69—the probability of a given member who feels moderately  against  an issue casting a vote  against  that issue

0.73—the probability of a given member who feels  neutral  about an issue casting a vote on that issue (whether for or against)

0.78—the probability of a given member who feels moderately  for  an issue casting a vote  for  that issue

0.81—the probability of a given member who feels strongly  for  an issue casting a vote  for  that issue

Thus, there appears to be a strong correlation between the preference a Delta party member has indicated and the vote that person eventually casts concerning that issue. No other range of probabilities shows as high a correlation. (Zeta would be second, with correlations between 0.70 and about 0.47. Apparently, these party members are more apt to vote if they are  against  an issue.)

Perhaps the graph makes more sense now. These IR questions take some getting used to, but do not worry about speed, especially at first. Take the time to understand them as best you can, and you will find that subsequent questions do not seem as challenging. Good luck with your studies.

- Andrew

rickyric395 · Answer

For all those like myself, who struggled with the language of this question,  GMATNinja  explained this question in YouTube video.

https://www.youtube.com/watch?v=xDJBNnRRNxs

Gemmie · Answer

1. Members of the   party are most apt to vote according to their previously stated preference regarding the issue of working-time reduction.

The probability for Delta group is higher than in most choices except Against (even in this case, it still ranks 2nd, only 0.1 less than the 1st - Zeta)

2. Members of the   party are most apt to vote against the issue of working-time reduction if their previously stated preference regarding the issue of working-time reduction was also against.

The question is related to   choice, in which Zeta probability is the highest (0.7)

Abbas007 · Answer

Official Explanation-

RO1: Recognize
For party members whose votes are most apt to match their previously stated preferences the probabilities will be greatest. The probabilities for the Delta party are greater than those for the other parties in most cases. The one exception is the data point on the far left of the graph, where the probability of the Zeta party is the greatest. Since, for each party, the previously stated preference is “against” for less than 10% of the party’s voters, this exceptional data point has little bearing overall on how apt members of the party are to vote their previously stated preference.
The correct answer is Delta

RO2: Infer
The data points directly above the horizontal axis label “against” represent members of the various parties whose previously stated preference was “against.” Of these data points, the one with the greatest probability represents the party whose members are most apt to vote against the issue.

The correct answer is Zeta.

KarishmaB · Answer

Here is a video solution to his problem:

https://www.youtube.com/watch?v=hcILCsZD1ic

Tucky · Answer

KarishmaB  I was going through the explanation. You mentioned that  ''   less than 10% of that party's voters had a previously...''  translates to more than 91% are  FOR . 
 But in the question, there is this whole range of options between AGAINST AND FOR. FOR can be any percentage, hence i am not sure about the weighted avg. logic.

For (1), i selected  DELTA  because probability of actual choices are most closely aligns with the probability of previously stated preferences, which will be 1.

Bunuel · Answer

Less than 10% “against” does not mean more than 90% “for.” It only means more than 90% are not in the “against” bucket, which includes the middle tick marks plus “for,” so you cannot compute any weighted average from that sentence.

For more, check complete solution  HERE .

KarishmaB · Answer

Tucky, I have taken simplistic integer values to explain the concept. The numbers 91 for and 9 against are one example of how the distribution could be. 
The concept is simply this: when there are various probabilities (e.g. for Delta 0.6, 0.7, 0.73, 0.79, 0.82) and you need to average them, you need to see how many people there are at each probability. We cannot average them by simply taking the mid value. 
They have told us that less than 10% are against which means others are not. For Delta, all other probabilities (not against) are higher than probabilities of all other parties.

The effect of voters previously stated preference regarding the issue

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The effect of voters previously stated preference regarding the issue

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