Q11 - A rise in the percentage

[rsmorale]

Will someone please help me with this Weaken question? I don't understand the gap, and how to exploit it.

[littlebibliophile]

So from the stim we know there was a rise in the percentage of 18-yr-old recruits and a rise in the percentage of high school dropouts. Because these rises correlate, the arguer concludes that recruitment rates for 18-yr-olds heavily depend on recruitment rates of high school dropouts.

(A) One thing I have learned about questions like this is that when the stim concerns itself solely with percentages, be instatnly wary of choices that say something about hard numbers. This about the actual number of 18 yr old grads, so it can't help or hurt the conclusion about the percentage of 18 yr old dropouts being recruited.

(B) only tells us that the army needs some graduates in order to operate high tech systems. This doesn't really tell us anything though, because they might need a minuscule percentage of grads, and the rest of the pool could be filled with dropouts.

(C) weakens the arg because it says the percentage of high school grads among the 18 yr old recruits rose sharply. If this is true, it seems that although the pool of dropouts is growing larger, the army is increasingly recruiting from the pool of grads, not drop-outs, which would mean that their recruitment rates are not depending heavily on drop-outs (They're looking elsewhere for the 18 yr olds they want to recruit)

(D) is a wishy-washy fact. Ok, so the army "encourages" them to finish school. That doesn't mean that they aren't recruiting those who don't finish the most.

(E) is about college education so it has nothing to do with weakening the stim, which is dealing with high school grads/dropouts

[giladedelman]

Great explanation!

[mcrittell]

Would B be correct if it had said "most" instead of "many"?

[aznriceboi17]

When choice C says

... the percentage of high school graduates among the 18-year-olds recruited in the republic ...

is it referring only to recruits of the armed forces? I was a bit worried when I looked at the answer choice because I thought it might have been referring more generally to the 18-year-olds recruited by ANY entity in the republic, in which case this wouldn't necessarily tell you that the percentage for the armed forces went up.

[ohthatpatrick]

I see your concern.

However, the conclusion itself doesn't specify "recruitment for the armed services". It just says "the republic's recruitment rates for 18 year olds". So if (C) is actually broader, it's still fine because the conclusion would be guilty of the same scope.

But in reality I think LSAT just expected us to continue thinking of "recruitment/recruits" in the original sense of the first sentence, 'recruited by the armed services'.

A lot of times LSAT uses "callback language" to something that was said earlier, and the 2nd iteration might not be a perfect match for the first. Naturally, sometimes that 2nd iteration might be too much of a stretch from the 1st iteration, in which case LSAT may test us on the assumption we'd be making in equating the two concepts. But other times, the differences are really subtle, in which case we're better off playing along like they're still talking about the same thing.

[aznriceboi17]

Thanks for that bit about the use of "callback language." I think I find myself spending too much time deciding whether the two uses are equivalent -- it'd probably be better to be less strict.

[contropositive]

I initially selected B because if the system requires only high school grads then it would weaken the argument that they recruit drop outs. However, during review, I saw the word "many" and I knew that I had made a mistake picking B. However, what if B said,

"the high-technology systems used by the republic's armed services can be operated only by individuals who have completed high school education"

would that make B right? it just taking off "many"

[ohthatpatrick]

You've definitely made (B) better by removing the "many" and implying that ALL high tech systems require high school grads.

However, the problem with (B) remains this: what percentage of armed services individuals actually operate the high tech systems?

If you picture a real armed service, there are obviously some people manning the radar screens, flying drones, etc. But aren't they vastly outnumbered by the soldiers who AREN'T sitting in front of a screen?

I would imagine that in our actual Army/Navy/Marines, etc., 20% or less of the soldiers are actually responsible for operating high-tech systems.

So even though the army would need high school grads to fill THOSE roles, the majority of soldiers would NOT need a high school education.

You may be thinking, "Patrick, you seem to be pulling in outside knowledge and/or pulling 20% out of your butt."

You are correct. But doing so protects me from caring too much about these high-tech systems. I don't have any idea how significant these high-tech systems are to the armed services in this stimulus. The jobs that (B) refers to might be a significant percentage of armed service jobs or a very negligible percentage.

Don't get me wrong: (B) does currently weaken the argument a smidge, and it would weaken the argument a slightly bigger smidge if we changed 'many' to 'all'.

We know from (B) that "at least SOME positions in the army cannot be filled by high school dropouts". But that's just not a very powerful weakening idea.

If (B) said something like "most positions in the armed services involve operating high-tech systems that can only be performed by those who have completed high school", then it would have much more teeth.

(C) is a much more powerful weakener because it's basically just supplying an alternative explanation for the percentage uptick.

The author thinks that the uptick in high school dropouts explains the uptick in armed service recruits.

(B) attempts to slightly undermine the plausibility of the author's explanation
(C) provides an alternative explanation for the statistic

Both of those can be valid attack points, but you should know that LSAT vastly leans towards rewarding the alternative explanation.

When I read this stimulus, I go to the answer choices with this question in mind:
"Given that I don't want to agree with the author's hypothesis that high school dropouts are the ones causing the uptick in recruits, what else could be causing the uptick in recruits?"

(C) is a weirdly direct answer because it basically just says, "it's high school grads".

[jasonleb1]

I don't understand how C is the stronger weakener compared to B. They don't specify that the increase in the percentage of graduates came at the cost of reducing the percentage of drop outs. Maybe they increased their percentage of graduate recruits from .0001% to 2% and drop outs still make up 98% of their recruits which would not weaken the conclusion that recruitment rates depend substantially on drop-outs.

I get why B is wrong, but I don't see how C is right.

[civnetn]

I don't understand how C is the stronger weakener compared to B. They don't specify that the increase in the percentage of graduates came at the cost of reducing the percentage of drop outs. Maybe they increased their percentage of graduate recruits from .0001% to 2% and drop outs still make up 98% of their recruits which would not weaken the conclusion that recruitment rates depend substantially on drop-outs.

I get why B is wrong, but I don't see how C is right.

I totally see where you're coming from, but there are a couple things to consider:

C) Mentions a "sharp" increase in the percentage of graduates. Which mean we're not talking about .0001% to 2%. I wouldn't consider that "sharp."

The increase in % of graduates vs % of dropouts has to add up to 100%. If your dropout rate is 50% and your grad rate is 50% but then skyrockets to 70%, if you didn't decrease % dropouts you'd be dealing with 120% of a select group of people. Which doesn't make sense.

50% of 100 is 50. 70% of 100 is 70. 70 + 50 is 120. But we're pulling from 100 ppl.

Make sense?

[HughM388]

I don't understand how C is the stronger weakener compared to B. They don't specify that the increase in the percentage of graduates came at the cost of reducing the percentage of drop outs. Maybe they increased their percentage of graduate recruits from .0001% to 2% and drop outs still make up 98% of their recruits which would not weaken the conclusion that recruitment rates depend substantially on drop-outs.

I get why B is wrong, but I don't see how C is right.

I totally see where you're coming from, but there are a couple things to consider:

C) Mentions a "sharp" increase in the percentage of graduates. Which mean we're not talking about .0001% to 2%. I wouldn't consider that "sharp."

The increase in % of graduates vs % of dropouts has to add up to 100%. If your dropout rate is 50% and your grad rate is 50% but then skyrockets to 70%, if you didn't decrease % dropouts you'd be dealing with 120% of a select group of people. Which doesn't make sense.

50% of 100 is 50. 70% of 100 is 70. 70 + 50 is 120. But we're pulling from 100 ppl.

Make sense?

You do understand that an increase from .0001% to 2% is an increase of 20,000x? That's an increase of several orders of magnitude, which is to say extremely "sharp." The person to whom you're responding—whose comment you determined "doesn't make sense"—knows exactly how percentages work, though it seems you may not. They were pointing out that the percentage could rise sharply and not meaningfully affect the numbers significantly. Your example, in which you showed us how to add to 120%, was therefore gratuitous.

(C) is very feeble as the correct answer, though I suppose it could be forced, after a lot of stretching, massaging, or even bludgeoning, to make sense, though (B) is probably stronger, overall, given the logical flaw inherent in (C). It's unfortunate that the correct answer is committing one of the flaws that the LSAT explicitly tests in other questions, as it confuses a sharp increase in percentage with a commensurately sharp increase in relative quantity. You could select (C) as the answer on exactly the same question and get it wrong later in the section.