Last year the rate of inﬂation was 1.2 percent, but for the current

Question

Last year the rate of inﬂation was 1.2 percent, but for the current year it has been 4 percent. We can conclude that inﬂation is on an upward trend and the rate will be still higher next year.

Which of the following, if true, most seriously weakens the conclusion above?

(A) The inﬂation ﬁgures were computed on the basis of a representative sample of economic data rather than all of the available data.

(B) Last year a dip in oil prices brought inﬂation temporarily below its recent stable annual level of 4 percent.

(C) Increases in the pay of some workers are tied to the level of inﬂation, and at an inﬂation rate of 4 percent or above, these pay raises constitute a force causing further inﬂation.

(D) The 1.2 percent rate of inﬂation last year represented a 10-year low.

(E) Government intervention cannot affect the rate of inﬂation to any signiﬁcant degree.

Argument Evaluation

Situation   
The rate of inflation was 1.2 percent last year but is 4 percent in the current year. It is therefore expected to rise above 4 percent next year.

Reasoning 
 What point most weakens this conclusion?  The conclusion is based on an  upward trend  that is derived from data for two years. Data from only two years provide rather weak evidence of a trend. Additional evidence that provides a context for the annual inflation rates during the most recent two-year period will promote a more solid evaluation of this prediction of next year’s inflation rate. If inflation has recently been  stable  at 4 percent, and the temporary drop the previous year is accounted for by lower oil prices, then the basis for the prediction seems quite weak.

(A) As long as the sample was representative, the figures should be accurate. This point does not weaken the conclusion.

(B) Correct . This statement suggests that the 1.2 percent inflation rate is an unusual occurrence in recent years. Especially because the dip below the stable 4 percent rate was  temporary , this unusual occurrence cannot be used as the basis for predicting a trend.

(C) This statement explains one process by which inflation increases and tends to support the conclusion that inflation will continue to rise.

(D) This information implies, for example, that two years ago, the inflation rate was higher than 1.2 percent. This raises the possibility (without stating it) that last year and the year preceding mark a trend of declining inflation (and that the current year’s 4 percent is an aberration). However, if the inflation rate two years ago was only slightly higher than 1.2 percent (for example, 1.25 percent), then it would be difficult to regard these two numbers as signaling a trend of declining inflation. We do not have enough information here to regard this as a significant weakener. The information is sufficient to justify a little doubt about the argument’s conclusion—but not at all specific enough to undermine the argument’s conclusion as much as does (B).

(E) The failure of government intervention to affect the rate of inflation could be seen to support, not weaken, the conclusion.

pqhai · Accepted Answer

Hi nitin

I'm glad to elaborate.

ANALYZE THE STIMULUS:

Fact:  Last year the rate of inflation was 1.2 percent, 
 Fact:  The current year it has been 4 percent. 
 Conclusion:  inflation is on upward trend and the rate will be still higher next year.

The question uses a popular  logical fallacy:   “Using several points to conclude a trend” .  KEYWORD  here is “ upward trend ”. To weaken the conclusion, you can show that the data provided in the stimulus does not represent the overall trend.

ANALYZE EACH ANSWER:

A) The inflation figures were computed on the basis of a representative sample of economic data rather than all of the available data.
 Wrong.  The point needs to be attacked is the result – upward trend,  not the method  (economic data vs all available data)

B) Last year the dip in oil prices brought inflation temporarily below its recent stable annual level of 4 percent.
  Correct.   Regularly, the inflation rate is 4%,  last year’s inflation rate is only the temporary case . So, the comparison between last year’s inflation rate with current year’s does not reflect the overall trend. ==> Weaken the conclusion.

C) Increases in the pay of some workers are tied to the level of inflation, and at an inflation rate of 4 percent or above, these pay rises constitute a force causing further inflation.
 Wrong.  Out of scope because  C goes too far . In addition, the key point to attack is the  invalid comparison between last year’s inflation rate and current year’s .

D) The 1.2 percent rate of inflation last year represented a 10 year low.
 Wrong.  If it’s true, how does it weaken the conclusion.  What if in the years before last year, the inflation rates were stable at 4%? .

E) Government intervention cannot affect the rate of inflation to any significant change.
 Wrong.  Out of scope. Nothing about “government intervention”.

Hope it helps.

KarishmaB · Answer

Last year inflation = 1.2%
Current year inflation = 4%

Conclusion: "Inﬂation is on an upward trend and the rate will be still higher next year."

We are concluding about the future of inflation rate - that there is an upward trend in the rate. That the rate will increase still further next year.
What will weaken this?

(A) The inﬂation ﬁgures were computed on the basis of a representative sample of economic data rather than all of the available data.

This doesn't imply that there may be no upward trend. As long as the figures give an accurate representation, they should be fine.

(B) Last year a dip in oil prices brought inﬂation temporarily below its recent stable annual level of 4 percent.

This option tells us that inflation stays stable at 4%. Last year was a "temporary" outlier because of dip in oil prices. So this year inflation would have been expected to be back at 4% and it was. This means there may be no upward trend. Hence it weakens our conclusion.

(C) Increases in the pay of some workers are tied to the level of inﬂation, and at an inﬂation rate of 4 percent or above, these pay raises constitute a force causing further inﬂation.

This helps our conclusion that if inflation is at 4%, it will go further up.

(D) The 1.2 percent rate of inﬂation last year represented a 10-year low.

There might have been a downward trend till last year so the 1.2% inflation was a 10-year low. It looks like the trend has reversed now. There is a big difference between option (B) and this one. Option (B) clarifies that last year was an outlier due to a "temporary" condition and every year inflation is expected to be 4%. So it says that there may be no trend. This option doesn't imply that there may be no trend. The trend might have been reversed.

(E) Government intervention cannot affect the rate of inﬂation to any signiﬁcant degree.

Irrelevant.

Answer (B)

mads · Answer

A)The inﬂation ﬁgures were computed on the basis of a representative sample of economic data rather than all of the available data. 
>> Not related.
(B)Last year a dip in oil prices brought inﬂation temporarily below its recent stable annual level of 4 percent. 
>> Yes. This explains the reasom for last year's inflation rate and also mentions 4 percent is the stable level. And so it weakens the argument that the inflation is increasing.
(C)Increases in the pay of some workers are tied to the level of inﬂation, and at an inﬂation rate of 4 percent or above, these pay raises constitute a force causing further inﬂation. 
>> Supports the argument.
(D)The 1.2 percent rate of inﬂation last year represented a 10-year low. 
>> This shows 1.2 is the 10 year low, but do not say if 4 is a higher value of an average value.
(E)Government intervention cannot affect the rate of inﬂation to any signiﬁcant degree. 
>> Not related.

thevenus · Answer

Last year the rate of inflation was 1.2 percent, but for the current year it has been 4 percent. We can conclude that inflation is on an upward trend and the rate will be still higher next year.
Which of the following, if true, most seriously weakens the conclusion above?

We need an AC which can tell us that this increment in inflation from 1.2% to 4% will not increase further.

(A) The inflation figures were computed on the basis of a representative sample of economic data rather than all of the available data.
 whatever data is taken; this AC is not weakening the conclusion. 
(B) Last year a dip in oil prices brought inflation temporarily below its recent stable annual level of 4 percent.
 Correct- this shows that the inflation went down to 1.2% due to oil price fall but regained to 4% , which is the stable annual rate. 
(C) Increases in the pay of some workers are tied to the level of inflation, and at an inflation rate of 4 percent or above, these pay raises constitute a force causing further inflation.
 not weakening;strengthening - incorrect 
(D) The 1.2 percent rate of inflation last year represented a ten-year low.
 doesn't signify anything about the further increase of inflation above 4%-incorrect 
(E) Government intervention cannot affect the rate of inflation to any significant degree.
 out of scope

ChrisLele · Answer

The 4% is used to suggest that inflation is growing. After all, if the inflation rate was 1.2% in the previous year, then surely that must be the case. However, if the 1.2% represented a lower inflation rate than usual, then an inflation rate of 4% cannot be used as evidence that inflation is an upward trend.

(A) nails this point and elaborates even further by stating that the usual inflation rate is 4%. Therefore, an inflation rate of 4% is a return to business as usual, not a sign of an upward trend in inflation.

nitin6305 · Answer

I almost understood the reasoning completely. 
My only doubt is with option D, " if all the years before last year the rate of inflation was more than 1.2% or lets say if it was stable 4%, and it dropped to 1.2% for just one year. Subsequently, the rate became stable again as 4% , so doesn't it mean that there is no  upward trend  ?"

pqhai · Answer

Hi nitin

You have a very good question.

There would be no upward trend, if  only  last year inflation rate dropped to 1.2%. Because:

(1) The conclusion is "  inflation is on upward trend and the rate  will be still higher next year  ". If the next year the inflation rate will be stable at 4%, you CANNOT conclude that the inflation is on upward trend, and the rate will be still higher.

(2) If you base only on data of two years (last year and current year) to conclude the upward trend, why don't you conclude the  downward trend  for the last year and the year before last year (4% ==> 2%). Hence, your conclusion is not strong enough to conclude the inflation is on upward trend.

Hope it's clear.

adg142000 · Answer

If you base only on data of two years (last year and current year) to conclude the upward trend, why don't you conclude the  downward trend  for the last year and the year before last year (4% ==> 2%).  Hence, your conclusion is not strong enough to conclude the inflation is on upward trend.

doesnt this mean it is also actually weakining the conclusion of upward trend

pqhai · Answer

Hi adg142000

This is just an example I used to clarify nitin's doubt about option D. Before answer your question, I just want to clarify D a bit.

D says: "The 1.2 percent rate of inflation last year represented a ten-year low". 
Thus, the inflation rates pattern should be:  HIGH  (the year before last year) ==>  LOW  (last year) ==>  HIGH  (current year).

I used my example to show: if we use only data  from last year to current year  to conclude inflation is on upward trend ==> we could be wrong. Because if we use data  from the year before last year to last year  ==> we can also conclude inflation is on downward trend.

Your question is:   does the second part (conclusion about downward trend) actually weaken the main conclusion? If it does, D may be right?

I would say no, the second part of my example just shows the comparison used in the stimulus is invalid. Because if can say the inflation is on upward by using only data of two years, we can also conclude the inflation is on downward by using data from other two years. The reverse pattern is also true, if we use only data from two years to conclude inflation is on downward ( It is your inquiry ), we can also use data from last year to current year to weaken the "new" conclusion (inflation is on downward). In short, D is not strong enough to weaken the main conclusion, because it's  half right, half wrong .

Hope it clears your doubt.

rrsnathan · Answer

I will try explaining this one!!!!

Conclusion: inflation is on an upward trend and the rate will be still higher next year.

Assumption: Inflation will always have a pattern
There are no unusual things happened to say that inflation rate will change

(A) The inflation figures were computed on the basis of a representative sample of economic data rather than all of the available data . - Irrelevant information 
(B) Last year a dip in oil prices brought inflation temporarily below its recent stable annual level of 4 percent.  - Weakener Says that Last year dip in Oil price brought the inflation down to 1.2 from stable point of 4. So same stable inflation point will be maintained unless there is no unusual dip in oil price, or.... 
(C) Increases in the pay of some workers are tied to the level of inflation, and at an inflation rate of 4 percent or above, these pay raises constitute a force causing further inflation.  - No point to say there will be increase in the Pay next year 
(D) The 1.2 percent rate of inflation last year represented a ten-year low.  - irrelevant - 10 years low inflation says nothing about the next year rate of inflation 
(E) Government intervention cannot affect the rate of inflation to any significant degree  - Again this has nothing to do with the next year inflation rate

Correct me if i am wrong.

Hovkial · Answer

OFFICIAL GMAT EXPLANATION

Argument Evaluation

Situation_____________The rate of inflation was 1.2 percent last year but is 4 percent in the current year. It is therefore expected to rise above 4 percent next year.

Reasoning___________What point most weakens this conclusion?  The conclusion is based on an  upward trend  that is derived from data for two years. Data from only two years provide rather weak evidence of a  trend . Additional evidence that provides a context for the annual inflation rates during the most recent two-year period will promote a more solid evaluation of this prediction of next year’s inflation rate. If inflation has recently been stable at 4 percent, and the temporary drop the previous year is accounted for by lower oil prices, then the basis for the prediction seems quite weak.

A As long as the sample was representative, the figures should be accurate. This point does not weaken the conclusion.

B Correct. This statement suggests that the 1.2 percent inflation rate is an unusual occurrence in recent years. Especially because the dip below the stable 4 percent rate was  temporary , this unusual occurrence cannot be used as the basis for predicting a trend.

C This statement explains one process by which inflation increases and tends to support the conclusion that inflation will continue to rise.

D This information implies, for example, that two years ago, the inflation rate was higher than 1.2 percent. This raises the possibility (without stating it) that last year and the year preceding mark a trend of declining inflation (and that the current year’s 4 percent is an aberration). However, if the inflation rate two years ago was only slightly higher than 1.2 percent (for example, 1.25 percent), then it would be difficult to regard these two numbers as signaling a trend of declining inflation. We do not have enough information here to regard this as a significant weakener. The information is sufficient to justify a little doubt about the argument’s conclusion—but not at all specific enough to undermine the argument’s conclusion as much as does (B).

E The failure of government intervention to affect the rate of inflation could be seen to support, not weaken, the conclusion.

Mraax · Answer

Inflation will be in upward trend if all data points are in equal and comparable years. LY could be low due to some special reason - Hence B - Temporary dip.

CrackverbalGMAT · Answer

Last year the rate of inﬂation was 1.2 percent, but for the current year it has been 4 percent. We can conclude that inﬂation is on an upward trend and the rate will be still higher next year.

Which of the following, if true, most seriously weakens the conclusion above?

Question type:  Weaken the argument

Conclusion:  Inflation is on an upward trend and the inflation rate will be higher next year.

Task at hand:  Find an option that shows that inflation is not necessarily on an upward trend and the inflation rate will not necessarily be higher next year

A. The inﬂation ﬁgures were computed on the basis of a representative sample of economic data rather than all of the available data.  Details of the sample that was taken into consideration will not help us show that that inflation is not necessarily on an upward trend

B. Last year a dip in oil prices brought inﬂation temporarily below its recent stable annual level of 4 percent.   This option is telling us that the stable annual level is 4 percent. This means that the rate of 1.2% is an exception. In other words, at the most, the rate the following year will go back to the recent stable. This shows that inflation is not necessarily on an upward trend.

C. Increases in the pay of some workers are tied to the level of inﬂation, and at an inﬂation rate of 4 percent or above, these pay raises constitute a force causing further inﬂation.  This option is saying that there will be further inflation. Strengthens.

D. The 1.2 percent rate of inﬂation last year represented a 10-year low.  This means that the rate could go high or low after this. Doesn’t weaken or strengthen.

E. Government intervention cannot affect the rate of inﬂation to any signiﬁcant degree.  This may be true, but this doesn’t help us show that that inflation is not necessarily on an upward trend.

- Nitha Jay

Dinesh654 · Answer

Hi,

I read the above posts, but still

I have issues with choices A and B.

To me, A seems like a classical weakner- doubting on the data (sample), suggesting that last year or this year's inflation could be inaccurate--> maybe its a downward trend, maybe inflation is stable--> therefore a good weakner!

In B --> last year dip was temporary and this years inflation is stable--> oil price could fall again or rise again, we don't know, trend could be upward or downward--> chances are we could se downward more likely.--> I do say its a weakner.

but A, can't be eliminated with 100% confidence. so its like a 50-50% situation,which will take extra time on the actual exam or a lucky guess.

GMATNinja · Answer

Here's the exact wording of (A):
 
The key to eliminating (A) is that the data sample is called  "representative,"  which implies that it was a GOOD representation of all available data. If (A) said the sample was  "unrepresentative,"  then (A) would weaken the argument. As written, though, (A) does not cast doubt on the validity of data sample, or the conclusion drawn from that data.

As for (B), you're right that it doesn't PROVE what will happen with the inflation rate next year. It does, however, give us reason to believe that last year's low inflation was a one-off event, instead of a trend that will continue into the new year.

(B) is the correct answer.

I hope that helps!

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