Somebody Please Explain this LR Question Forum

[arabic06]

PT25,Q25,S1

The answer is (B). I understand the comparison of percentages and absolute numbers here, but the reason I think (B) makes sense is because although this survey question answered with a higher percentage choosing one way, and only 35 percent the other way, it was only a sample of the population, thus this requirement would be necessary if actually true, but we can't say this is sufficient for the population at large. We would need more information. BUT, then why not (A)? Please help!

[Campagnolo]

I'd take this down quick snap before you get busted up about it.

It's a problem to post complete questions. Try putting it up in your own words, or think of an analogous idea that we can work with.

[ben4847]

and to think I got a 176 without knowing what a sufficient or necessary condition is.
Ha ha ha ha

[Campagnolo]

Also: "only if" introduces the necessary condition.

[ben4847]

I'd take this down quick snap before you get busted up about it.

It's a problem to post complete questions. Try putting it up in your own words, or think of an analogous idea that we can work with.

Does this work?

edit: gosh, if you're pulling it down, I don't know enough copyright law to leave my version up either

[arabic06]

In this problem, what does the sufficient and necessary condition apply to?

[NomNom]

You need to understand "only if" in this one. I am not going to go into a lot of details since the question should not be reposted as this, but think about the logic behind being convicted and being indicted and then think about the "only if" statement. The answer is in there.

[NomNom]

I will add that A) is trying to trick you in that usually the "sample population" questions that are correct are from arguments that base the conclusion off of something like "10 gym teachers were asked about stock trading..". In this one, it is simply saying that X number of people. Well, you don't know who those people are...they very well may BE representative of the population. It's almost just restating part of the argument that people were polled in the first place. No kidding. Look for why an answer is wrong before looking for why one is right.


....and edit your first post to remove the question because it is a violation. You can also just quote the PT and section number instead of typing it out.

[arabic06]

Actually, I think the focus is on numbers and percentages, not "only if." I believe (B) makes sense because if this were really true, when sampled from a population, the percentage would have to be higher for the former group, but that does not necessarily mean that it is sufficient to say that is true for the whole population. How do you explain (A) as being incorrect?

[NomNom]

See my answer above regarding A.

The two groups in the question are apples and oranges (see the only if).

I say again work on the elimination process...you don't have to completely grasp B because it isn't a correct answer that is going to jump out at you. You can eliminate A) for reasons I stated above. B)??? C) Ambiguity? Eliminate. D) Eh? E) Not supported.

[arabic06]

Yes, you indirectly pointed out how "sample/population" questions are answered on other tests. However, you did not directly explain why (A) is wrong and why (B) is right. CAN YOU ARTICULATE WHY (B) IS RIGHT AND WHY (A) IS WRONG?

[arabic06]

OKAY WHY IS (B) CORRECT? WHAT DO THE NECESSARY AND SUFFICIENT CONDITIONS REFER TO, GROUPS, NUMBERS, PERCENTAGES?