A comparison of the output of two spinning mills that produce

Question

A comparison of the output of two spinning mills that produce woolen yarn—the Costello Mill and the Moorhead Mill—showed that the yarn from the Costello Mill had fewer flaws and greater strength. Since the Costello Mill's process differs from the Moorhead Mill's only in the way that the raw wool is treated before spinning, the treatment that the Costello Mill uses must be responsible for the superiority of its yarn.

The reasoning above assumes which of the following?

A. The Moorhead Mill's raw wool is at least as well suited as the Costello Mill's is for producing yarn of the quality that the Costello Mill produces.
B. Strength and freedom from flaws are not the only two properties that can be used in judging the quality of yarn.
C. The Moorhead Mill's yarn is intended for the same market and the same price range as the Costello Mill's yarn.
D. The treatment that the Costello Mill gives to raw wool before spinning is no more costly than the treatment that the Moorhead Mill uses.
E. The Moorhead Mill does not have a significantly larger annual output of woolen yarn than does the Costello Mill.

MartyTargetTestPrep · Accepted Answer

A comparison of the output of two spinning mills that produce woolen yarn—the Costello Mill and the Moorhead Mill—showed that the yarn from the Costello Mill had fewer flaws and greater strength. Since the Costello Mill's process differs from the Moorhead Mill's only in the way that the raw wool is treated before spinning, the treatment that the Costello Mill uses must be responsible for the superiority of its yarn.

We see that passage presents a scenario in which one spinning mill, Costello, produces yarn with fewer flaws and greater strength than are had by the yarn produced by another mill, Moorhead. Then, since the processes the two mills use to produce yarn differ in only one way, the way the raw wool is treated before spinning, the author concludes, "the treatment that the Costello Mill uses must be responsible for the superiority of its yarn."

Then, the question asks the following:

The reasoning above assumes which of the following?

So, the correct answer will state an assumption upon which the argument depends.

Let's go to the answer choices.

A. The Moorhead Mill's raw wool is at least as well suited as the Costello Mill's is for producing yarn of the quality that the Costello Mill produces.

This choice is interesting. It brings up another possible reason for the for the difference in quality between the two mills' yarns, the quality of the raw wool.

If this choice is not true and the Moorhead Mill's raw wool is NOT at least as well suited as the Costello Mill's is for producing yarn of the quality that the Costello Mill produces, then the fact that the Costello Mill's process differs from the Moorhead Mill's only in the way the raw wool is treated no longer provides convincing support for the conclusion of the argument.

After all, if the Moorhead Mill's raw wool is NOT at least as well suited as the Costello Mill's is for producing yarn of the quality that the Costello Mill produces, then it could be that the quality of the raw wool, rather than the difference between the ways wool is treated, is the cause of the difference in quality between the two mills' yarns.

So, for the argument to work, it must be the case that what this choice says IS true. In other words, the argument depends on this choice being true in order for the evidence provided to support the conclusion.

Keep.

B. Strength and freedom from flaws are not the only two properties that can be used in judging the quality of yarn.

The argument is about the quality of yarn as defined by "strength and freedom from flaws." So, it certainly does not depend on there being other "properties that can be used in judging the quality of yarn."

C. The Moorhead Mill's yarn is intended for the same market and the same price range as the Costello Mill's yarn.

This choice is vaguely related to the argument but goes off in a different direction, the topic of what Moorhead Mill's yarn is intended for.

If the conclusion of the argument were about whether Moorhead should improve the quality of its yarn or whether Costello will sell more yarn or something else about the two mills competing in the marketplace, then the argument might depend on what this choice says.

However, the argument is simply about the cause of the difference in quality of the yarns, and arriving at the conclusion does not depend on any assumption about prices or what markets the yarns are intended for.

Eliminate.

D. The treatment that the Costello Mill gives to raw wool before spinning is no more costly than the treatment that the Moorhead Mill uses.

This choice is a trap choice. If we weren't paying close attention, we could get the sense that the argument is that Moorhead Mill SHOULD USE Costello Mill's process. In that case, it might make sense that the author would assume that the treatment that the Costello Mill uses is no more costly than the treatment that the Moorhead Mill uses. After, cost would be a factor in determining which treatment a mill should use.

However, since the conclusion is not that Moorhead Mill should use Costello Mill's process but rather simply that the difference in treatment is the cause of the difference in quality, the argument does not depend on what this choice says.

Eliminate.

E. The Moorhead Mill does not have a significantly larger annual output of woolen yarn than does the Costello Mill.

This choice is a trap. It gives us material for creating a story about the two mills. Maybe we start thinking something along the lines of that the difference in quality of the two mills' yarns has something to do with a difference in output of the two mills.

For instance, we could think, "Maybe Moorhead Mill would produce more yarn by producing yarn faster and, as a result, would produce yarn of lower quality than Costello Mill's yarn. So, the author must be assuming that the Moorhead Mill does NOT have a significantly larger annual output of yarn. Otherwise, there would be an alternative cause of the difference in quality of the yarns, and that alternative cause would be faster production."

To avoid making up such a story, we can do two things.

One is to see that we really don't have support for such a story. In other words, we have no clear reason to believe that faster production or greater output would result in lower quality yarn.

The other is to see that the passage states that "Costello Mill's process differs from the Moorhead Mill's only in the way that the raw wool is treated before spinning." So, we know for a fact that, even if this choice is not true and the Moorhead Mill DOES have a significantly larger annual output, the processes the mills use are still the same.

So, the argument does not depend on what this choice says since the conclusion about the cause of the difference in quality doesn't depend on assuming anything the outputs of yarn of the two mills.

Eliminate.

We see that the only choice that works is  (A) .

Paras96 · Answer

The argument concludes that the treatment used by the Costello Mill for raw wool must be responsible for the superiority of its yarn compared to the Moorhead Mill's yarn. To make this conclusion, the argument relies on certain assumptions. Let's evaluate each answer choice:

(A) The Moorhead Mill's raw wool is at least as well suited as the Costello Mill's is for producing yarn of the quality that the Costello Mill produces.
 - This option directly addresses the assumption in the argument. The argument assumes that the raw wool used by both mills is comparable in quality. If the Moorhead Mill's raw wool were not as well-suited, it could explain the difference in yarn quality without relying solely on the treatment process. Therefore, option (A) challenges the argument's assumption and is the correct answer.

(B) Strength and freedom from flaws are not the only two properties that can be used in judging the quality of yarn.
 - This option introduces the idea that there may be other properties to consider when judging yarn quality, but it doesn't directly address the assumption about the raw wool and treatment process.

(C) The Moorhead Mill's yarn is intended for the same market and the same price range as the Costello Mill's yarn.
 - This option doesn't directly address the assumption about the raw wool and treatment process. It deals with the market and price range of the yarn but doesn't challenge the assumption.

(D) The treatment that the Costello Mill gives to raw wool before spinning is no more costly than the treatment that the Moorhead Mill uses.
 - This option challenges the assumption based on cost, but it doesn't directly address the suitability of the raw wool. The argument's assumption is more about the quality of the raw materials, not the cost of treatment.

(E) The Moorhead Mill does not have a significantly larger annual output of woolen yarn than does the Costello Mill.
 - This option doesn't directly address the assumption about the raw wool and treatment process. It deals with the annual output but doesn't challenge the assumption.

In summary, option (A) directly addresses the assumption in the argument by suggesting that the quality of the raw wool used by the Moorhead Mill is comparable to that used by the Costello Mill. If the Moorhead Mill's raw wool were less suited for producing high-quality yarn, it would support the argument's conclusion that the treatment process is responsible for the superiority of Costello Mill's yarn. Therefore, option (A) is the correct answer.

GmatKnightTutor · Answer

A comparison of the output of two spinning mills that produce woolen yarn—the Costello Mill and the Moorhead Mill—showed that the yarn from the Costello Mill had fewer flaws and greater strength. Since the Costello Mill's process differs from the Moorhead Mill's only in the way that the raw wool is treated before spinning, the treatment that the Costello Mill uses must be responsible for the superiority of its yarn.

The reasoning above assumes which of the following?

A. The Moorhead Mill's raw wool is at least as well suited as the Costello Mill's is for producing yarn of the quality that the Costello Mill produces.
B. Strength and freedom from flaws are not the only two properties that can be used in judging the quality of yarn.
C. The Moorhead Mill's yarn is intended for the same market and the same price range as the Costello Mill's yarn.
D. The treatment that the Costello Mill gives to raw wool before spinning is no more costly than the treatment that the Moorhead Mill uses.
E. The Moorhead Mill does not have a significantly larger annual output of woolen yarn than does the Costello Mill

The passage talks about two mills that produce yarn: Mill C and Mill M. They use the same spinning process but C produces better yarn than M. The only difference between the two mills is that C's yarn, the better yarn, is treated differently before spinning. And that this must be the reason why it is better.

What is an assumption?

(A) is the answer. If the raw wool that Mill M uses is not as good ("suited") to make yarn to the quality that Mill C makes, it wouldn't make a difference whether you spun it the same way.

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Gemmie · Answer

Breakdown of the Argument
 
  Observation : Costello Mill's yarn has fewer flaws and greater strength than Moorhead Mill's yarn. 
  Difference in Process : The only difference between the two mills' processes is the treatment of raw wool before spinning. 
  Conclusion : The treatment of raw wool at Costello Mill must be responsible for the superior quality of its yarn.  
 Key Assumption

For the conclusion to be valid, it must be assumed that all other factors affecting yarn quality are equal between the two mills, except for the treatment of raw wool.

A.  The Moorhead Mill's raw wool is at least as well suited as the Costello Mill's is for producing yarn of the quality that the Costello Mill produces.

=> This is a critical assumption. If the raw wool quality at Moorhead Mill is inferior, it could be the reason for the lower yarn quality, not the treatment process.

B.  Strength and freedom from flaws are not the only two properties that can be used in judging the quality of yarn.

This introduces other potential quality measures but does not affect the argument's core reasoning about the treatment process.

C.  The Moorhead Mill's yarn is intended for the same market and the same price range as the Costello Mill's yarn.

This is about market and price, not directly about the cause of yarn quality differences.

D.  The treatment that the Costello Mill gives to raw wool before spinning is no more costly than the treatment that the Moorhead Mill uses.

Cost considerations do not impact the reasoning about the cause of the yarn quality differences.

E.  The Moorhead Mill does not have a significantly larger annual output of woolen yarn than does the Costello Mill.

Output volume does not impact the argument about the treatment process affecting yarn quality.

Nikhil17bhatt · Answer

@Experts  MartyTargetTestPrep , wanted to touch base on option D

If Option D says 
The treatment that the Costello Mill gives to raw wool before spinning is no better than the treatment that the Moorhead Mill uses.

Then can you please tell me which Option will be the right answer?

MalachiKeti · Answer

AjiteshArun   MartyTargetTestPrep

Here is why I eliminated A and Kept E

The comparison of output showed - fewer flaws + greater strength
Lets say output of Costello is 1000 and that of Moorhead is 100000000 - then the number of flaws in Costello is likely to be less than Moorhead. So having comparable output helps. Ofc if fewer flaws means fewer proportion of flaws then this logic breaks

Eliminated A because it says that the raw wool is of comparable quality of costello. So are we saying that if we negate this assumption and say that raw wool is not of comparable quality then the conclusion that since process only differs by a single step and thereby the process is responsible for superiority is challenged because now we might have 2 variables - poor raw material and process. So can we suddenly talk about a completely new variable?

AjiteshArun · Answer

Hi MalachiKeti,

Yes. Bringing a new variable in is a very common way to weaken something. Similarly, removing such weakeners is  a common pattern  in assumption questions.

As far as your point about the total output is concerned, look at what the stimulus says: "the yarn from the Costello Mill had fewer flaws and greater strength". Now what comes to your mind when we say something like that? Are we examining all the yarn produced by the mill to count the absolute total number of flaws?

The more likely interpretation is that we're talking about  a unit of production, not all production . This means that to mark E we'd need to assume that there's something about quantity that can affect quality, independent of the process. This isn't impossible, but it's a stretch, at least in comparison with option A. Option A tells us that the raw material is ~the same, and therefore it's more likely that the superiority of Costello's yarn is due to the (one) way its process is different from Moorhead's process.

MalachiKeti · Answer

AjiteshArun this is fantastic way of thinking - most of the times in practical world too the output of two factories won't necessarily be equal so that is definitely not an assumption required because we will be looking at the AVERAGE quality of the yarn produced per unit where unit could be a single spool/batch etc. Comparing total yarns that are flawed is stupid and doesn't convey anything at all - after all both have same processes except one step so why will suddenly quantity affect quality! Makes total sense now.

Thanks for a better way of thinking! The alternative example was great as well!

Thanks for a better way of thinking! The alternative example was great as well!

AjiteshArun · Answer

Happy to help.

Also, don't worry about having looked at total production. We absolutely need to explore edge cases in some CR questions. The trick is to try to minimise that, especially if another option gives us a more direct path.

VerbalBot · Answer

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A comparison of the output of two spinning mills that produce

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