#8 - The local agricultural official gave the fruit growers

[Administrator]

Complete Question Explanation

WeakenX-CE. The correct answer choice is (A)

The official’s argument is that since a new pesticide has been applied, the proportion of pears lost to insects was significantly less than it had been during previous period. Thus the new pesticide was more effective than the old one, at least in the short term.

Answer choice (A): This is the correct answer choice. This answer choice suggests that the amount of fruit that the District 10 produces has been declining for the past eight years due to the declining number of mature pear trees. It does not, however, change the fact that the proportion of pears lost to insects was significantly less due to the new pesticide, and as such does not weaken the argument.

Answer choice (B): This answer weakens the argument because it suggests an alternate cause for the declining proportion of pears lost to insects.

Answer choice (C): This answer weakens the argument because it also suggests an alternate cause for the declining proportion of pears lost to insects.

Answer choice (D): This answer weakens the argument because it suggests the loss of habitat for some of the insects as an alternate cause for the declining proportion of pears lost to insects.

Answer choice (E): This answer weakens the argument because if the effects of pesticides are cumulative, then the accumulation of pesticides could be the reason for the declining proportion of pears lost to insects. This casts doubt on the claim that the new pesticide was more effective than the old one.

[LSAT2018]

Does proportion here refer to a percentage? I chose (A) because numbers and percentages cannot be compared. Is that why answer (A) which cites the number/amount is ineffective in weakening the argument?
So in questions like these, would it be possible to automatically eliminate based on the number and percentage discrepancy?

[Adam Tyson]

Proportion does refer to percentage, LSAT2018, and so we might be on our toes here for a problem with the numbers. The authors gave us answer A hoping that we would focus on the numbers issue and forget that this is about whether the pesticide is effective at preventing loss to insects rather than about more or less fruit. This answer, about fewer trees, might help us explain less fruit, but it tells us nothing about the effectiveness of the pesticide.

The other four answers all give us alternate causes for the changing percentage of fruit lost to insects, so they all weaken the argument. A does not address the causal claim at all, and that makes it a winner. Good job!

[andriana.caban]

Hi,


So, I actually didn't eliminate (A) for the reasons above. Instead, the "in part" portion of the stimulus indicated that there were other factors for the amount of fruit that an orchard produces. So, does it really matter if the number of mature trees are declining? One of the other factors contributing to the amount of fruit could rectify the decline of the mature trees.

Please let me know if my thought process was correct - I don't understand the conversation above in relation to proportion / percent. (Hint: I'm horrible at any and all mathematical concepts).

Best,
Andriana

[Robert Carroll]

Andriana,

The issue is not "in part", because even if the explanation in answer choice (A) were the only factor, it wouldn't affect the argument. Nothing about mature trees tells us whether the declining proportion of insect losses is due to the new pesticide or to some other factor.

The percent issue also shows why answer choice (A) doesn't weaken the argument. Imagine the argument is different. If the author said something like "The coop lost 10 pears instead of 50, showing the number of pears lost declined. Therefore, the pesticide is working." Well, maybe the number went down because a bunch of trees burned down - you can't lose many pears to insects if the pears have burned up anyway. If the stimulus argument were about numbers of pears, not proportions, then answer choice (A) would provide a possible explanation of why the number lost would go down, even if the pesticides weren't the cause. But this is irrelevant to the argument we have, which is about percents.

Robert Carroll

[bbjigglercakes]

Complete Question Explanation

WeakenX-CE. The correct answer choice is (A)

The official’s argument is that since a new pesticide has been applied, the proportion of pears lost to insects was significantly less than it had been during previous period. Thus the new pesticide was more effective than the old one, at least in the short term.

Answer choice (A): This is the correct answer choice. This answer choice suggests that the amount of fruit that the District 10 produces has been declining for the past eight years due to the declining number of mature pear trees. It does not, however, change the fact that the proportion of pears lost to insects was significantly less due to the new pesticide, and as such does not weaken the argument.

Answer choice (B): This answer weakens the argument because it suggests an alternate cause for the declining proportion of pears lost to insects.

Answer choice (C): This answer weakens the argument because it also suggests an alternate cause for the declining proportion of pears lost to insects.

Answer choice (D): This answer weakens the argument because it suggests the loss of habitant for some of the insects as an alternate cause for the declining proportion of pears lost to insects.

Answer choice (E): This answer weakens the argument because if the effects of pesticides are cumulative, then the accumulation of pesticides could be the reason for the declining proportion of pears lost to insects. This casts doubt on the claim that the new pesticide was more effective than the old one.

Hi!,

im still honestly very confused about how A) could be the correct answer
it literally says the "amount of fruit an orchard can potentially produce depends, in part on how many mature trees it contains, and the number of mature pear trees in distc. 10 has declined steadily in the past eight years"

so fruit in part depends on the loss of mature fruit trees and mature fruit trees are declining and in part this is the reason why pears are also declining?

B) makes more sense to me because if there is pesticides that are helping reduce pear loss to insects then isnt that one (some) type of abatement program because it is a program that is helping prevent losses.....
i see that abatement does not equal fruit loss but to me it does... how would abatement be diff than pesticide they are both programs to reduce loss

[Robert Carroll]

bbjigglercakes,

The stimulus is trying to explain why the proportion of pears lost to insects was lower after the new pesticide was used. Answer choice (A) is saying that the number of trees is declining. So...there are fewer trees, and thus fewer pears out there. Nothing about that affects whether the proportion of fruit lost to insects would decline - fewer pears does not mean a lower proportion of fruit at all. Let's say the number of mature trees is down from 100 to 50. Let's say a mature tree produces 10 pears per tree. Then there used to be 1000 pears, and now there are 500. But...what proportion was lost to insects? Nothing about answer choice (A) clarifies that, and the only information we have in the stimulus is in a premise - "the proportion of pears lost to insects was significantly less than it had been during the previous three-year period". So the proportion was, say, 10%, and now is 5%. So 100 pears used to be lost to insects (10% of 1000), and now 25 are (5% of 500). The reduced number of mature trees can explain the reduced number of pears lost, but not the reduced proportion lost - look at my hypothetical. The number of pear trees is cut in half, which could easily explain a 50% reduction in pears lost to insects. But in fact, in my situation, there is a 75% reduction in numbers of pears lost to insects, because we not only have a smaller number of trees but also a smaller percent of the remaining trees that are affected by insects. Answer choice (A) still has a greater reduction in pears lost to insects than the decline in the numbers of mature trees alone could explain, so it does not weaken the argument. Why an unexpectedly lower number of pears lost? The only explanation we have is the pesticide...but then that certainly doesn't weaken the argument.

Answer choice (B) talks about a variety of insect-abatement programs. It certainly wouldn't help the argument that a particular one of them was the reason why - it would weaken that argument. The more things the farmers have been doing over the same period, the less need we have to attribute improvement to any one of them, which is what the conclusion is trying to do.

Robert Carroll