Paleontologists believe that fragments of a primate jawbone unearthed

one more D.

Reasons:

1. Estimated... to be
2. Fragments...provide

finley, my eyes search for OA, if I know ...OA is in white color . Appreciate, if u dont post the OA till there are atleast 10 responses.

I guess the trick is to understand the difference between 'estimated at' and 'estimated to be'. Since at is a preposition, it should be followed by a noun, whereas 40 to 40 million years old is not. Hence the structure is inaccurate. Furthermore 'estimated to be' is the proper idiomatic usage which includes the infinitive to make sure a valid range can be described.

Good one zazoz!

Regards,
A

"fragments" is plural so the only possible options are (A) and (D).

"estimated at" vs "estimated to be" - "estimated to be" is better. Choose (D).
So yes, for this example, you need to know this idiom..

D it is.

Guys, Does estimate as have a correct usage ?

I just see estimate to be in Manhattan , so just checking.

Thanks for the reply Mike ,

But in the problem from gmat prep

With surface temperatures estimated at minus 230 degrees Farenheit, Jupiter's moon Europa has long been considered far too cold to support life, its 60 square miles of water though to be frozen from top to bottom

"estimated at" is used in non underlined portion. So I mentioned the same in post above.

Dear targetdec31,
Hmmm. On a few occasions, unfortunately I have seen inconsistencies in the GMAT's own material, and it usually shows up in this form --- something never would be right in an underlined section is presented as part of the non-underlined (theoretically correct) part of the sentence. I suspect this is because the GMAC folks generate a large number of possible questions and then subject those questions to an extensive "experimental" testing period, during which focus is on the underlined portion and the alternatives --- after all, that's what determines the quality of the question. I imagine that the non-underlined portion simply does not receive the same level of scrutiny, such that sometimes something like this will slip through in the non-underlined section. Nobody's perfect, not even the people who write the GMAT.

All I can say is --- "estimated to be" is the correct idiom, and "estimated at" would never be correct as an alternative to an underlined section of a GMAT SC question.

Does this make sense?

Mike

Most likely not. Stick to the ones mentioned above.

You can also reference a video explanation provided here:

In this question how two verbs(estimated and provide) are present without any conjunction?

I guess estimated & unearthed are verb-ed modifier here .
Please explain.

Dear Abid,

I think you've already answered your own question! "Unearthed" and "estimated" are modifiers, so "estimated" is not parallel to "provide", and no conjunction is needed. One way to be sure of this is to remove the modifiers and see whether the subject and verb still make sense:

Paleontologists believe that fragments of a primate jawbone provide evidence of a crucial step along the evolutionary path that led to human beings.

"Fragments... provide" makes perfect sense.

Regards,
Meghna

Idiom question. Hope the gmat doesn't test such idioms anymore.

Dear Ergenekon,

Despite rumors to the contrary, idioms are alive and well on the GMAT. See:
https://magoosh.com/gmat/2013/how-import ... orrection/

You may find this ebook helpful:
https://magoosh.com/gmat/2013/gmat-idiom-ebook/
Much of that same information is also available in flashcard form:
https://gmat.magoosh.com/flashcards/idioms

I hope this helps!
Mike

Thanks Mike. I also thought about it. But why do you think we can get a conclusion based on og13 questions? We do not have any reason to believe that the gmat regards its guides as much as its real exam questions. Having mostly not clear explanations for og problems shows otherwise. In addition, questions in which idioms can be used to find the right answer do not prove that those questions can only be answered by idioms. In my opinion, the gmat products have value only because they are official questions. However, their products are very low - quality. If there was another company with the official questions (in theory), I am sure the gmac would just go bankrupt:). I bought exam pack 1 and was disappointed a lot. For 50 dollars(or more) they provided me with question from gmat paper. So we can't assume that the gmac paid really serious attention to this case in og 13.

Dear Ergenekon,

My friend, I would urge you to be mindful of your words. The GMAT practice questions are exceptionally high quality: the explanations in the official material are often not quite as good, and sometimes, you will get better explanations from other GMAT experts. Nevertheless, the questions themselves have been subject to several stages of trial--- they have been refined in fire, and have emerged as pure gold. I will admit that some of the OG explanations are sub-standard, but don't judge the question quality by the explanation quality.

My friend, when you speak poorly of such a high quality product, it actually makes you look bad. It implies that you are assigning blame for what you fail to understanding. You have to be very careful about putting such speech out in public, in a place in which anyone could read it. What if a business school adcom, or potential employer, or potential partner saw what you were saying? It's always worth putting your best self forward in a public space.

It may be true that the composition of questions on any particular real GMAT is not precisely the same as the composition we see in the OG, but we have to assume that it's representative on average. Idioms are an important topic, precisely because they are about understanding the "feel" of the language. This is something particularly hard for non-native speakers to appreciate, but it's absolutely crucial on the GMAT SC. It's true that most incorrect answers in the GMAT SC are incorrect for more than one reason, but mistakes in idiom are clear and valid reasons for any answer choice to be incorrect, and anyone who wishes to excel on the GMAT SC cannot afford to neglect idioms.

If there are some questions in the OG or in Exam Pack #1 that you feel are not clear, or for which the official explanations leave you unsatisfied, please post them here on GMAT Club. Actually, search for them first, because no doubt such questions have been posted already. Find those threads, and read what the experts have to say. You are more than welcome to solicit my aid if you would like my opinions. Yes, the OG explanations are of varying quality, but do not doubt the high quality of the questions themselves.

Finally, here's a blog that you may find helpful:
https://magoosh.com/gmat/2014/how-to-imp ... bal-score/

Mike

Mike, glad to discuss this with you. However, I don't know why you decided I spoke badly about the quality of questions. Although I encountered several times when Stacey and Ron from manhattan gmat mentioned that they did not like several questions by the gmat, I did not claim such thing in my previous post. I clearly expressed my thoughts on gmat products, which include official guide and exam pack 1. I think you would agree with me that the gmat exam has changed enough for many years. So providing too old questions as an exam pack 1 to exam takers is not a good idea. The whole purpose of my post was that your assumption that gmac takes its product - in this case og 13th- so serious as to make it a real representative of real exam is unwarranted. We don't know why they chose exactly those questions which are in og 13 and not other ones. In addition, I don't have much problems with explanations of gmat questions, although sometimes I notice that even experts have different explanations of the same question.

Dear Ergenekon,
My friend, please forgive me if I misattributed certain motives or interpretations to you without cause. In your prior post, you said:
"We do not have any reason to believe that the gmat regards its guides as much as its real exam questions. Having mostly not clear explanations for og problems shows otherwise."
This is what lead me to believe you were critical of the OG explanations.

I was not aware that Stacey or Ron from MGMAT ever spoke badly about any official questions. Those are two seriously brilliant people for whom I have tremendous respect, and I have never heard them say anything negative about the questions.

Yes, the GMAT has evolved over the years, but many of the standards have remained the same. Some of the old questions might have been released years ago, but in many ways, they are still representative of the standards that the GMAT still maintains. All test questions, even older test questions, have been through a rigorous vetting process, so they are uniformly on a much higher level than almost all other test prep questions from other sources.

I don't know for sure, but my understanding is that the questions that make it into the OG are among the better questions that the GMAT chooses to retire. There is a tremendously long selection process, whereby questions are vetted and refined and entered into the active pool of live test questions. Every now and then, for exam security, they remove some questions from that pool, and I think they choose some of the better quality questions from among these for the OG. I think we have good reason to suspect that the overall selections of topics --- say, the kinds of grammatical issues in SC --- are more or less representative of the distribution in their live question pool. Certainly, that is the implicit claim of their products.

In my view, nothing about the quality of the questions suggests in the least that there is anything suspect about the products as a whole. I have met some of the people at GMAC, and I have been very impressed with their concern for presenting a rigorous and fair product. While their primary concern is for the live test itself, this concern also extends to all the products they offer. They are deeply concerned with maintaining a consistent high quality across brand.

I would urge you to find out a little more about this company and how it operates. I am not easily impressed, and I have been impressed by this company.

Mike

I don't think this is true. In the following official question, the correct answer says "dated AT 34 million years old".

fossils-of-the-arm-of-a-sloth-found-in-puerto-rico-in-80744.html

Perhaps "estimated to be" is the only correct idiom and people have been wrong in saying "estimated at". Interesting grammar rule that I otherwise would have been unaware of.

GMATNinja
Dear Charles,
could you elaborate, are the following sentences correct?

- Company was estimated at $3 million
- The power of hydroelectric station is estimated at 13 MW

If no, why the official GMAT question utilized this construction in the Non-underlined portion of the sentence?

- With surface temperatures estimated at minus 230 degrees Farenheit, Jupiter's moon Europa has long been considered far too cold to support life, and with 60 square miles of water though to be frozen from top to bottom

Thank you in advance.