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#14- The number of serious traffic accidents (accidents

SLF
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With regard to LSAT #54, Section #2, Question #14, how should I discriminate correctly between answer choices 'C' and 'E'?
Lucas Moreau
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Hello, SLF,

E is not the best answer choice for this question. The term "serious accidents" is defined at the beginning of the stimulus, and there is no indication that its meaning drifted at all over time. (Besides, if E is right, does that mean that accidents that caused immediate death aren't serious?! :0 )

C is better, since it is providing an alternate cause for the conclusion asserted. For Weaken questions like this one, you're not just trying to disprove the conclusion: you're trying to show that the stated premise(s) do(es) not lead to the conclusion.

In this case, the assertion is that the lowered speed limit was the cause of the lowered rate of serious accidents. If C is true, however, then that provides a significant possible alternate cause for the conclusion asserted - and that would weaken the argument more than any other of the answer choices.

Hope that helps,
Lucas Moreau
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SLF
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Thanks Lucas. Great explanation.

My stumbling block was that the question stem directed me to treat the answer choices as if they were true...so I took that to mean that I should not question an answer choice.

Then, I was evaluating C and E in relation to the conclusion...which seemed to me to be more about what happened from 1986 and on...and although C seemed like a more logical and reasonable answer choice...it was also about the full 10 year time spectrum...and so I (erroneously) rejected C on that basis.
jgabalski
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Would someone mind helping me to explain why answer choice A is a bad answer here? I understand why C is correct, but am still stuck on A.
The conclusion that that the lowering the speeding limit reduced the number of serious accidents.
So essentially: Lower speeding limit --> less speeding (implicit) --> less serious accidents.

Answer choice A says that the number of tickets issued annually across the 10 year span stayed roughly constant, which means that there was no decrease in speeding after 1986? So if there was no decrease in speeding, then the lowering of the speeding limit had not effect? So if the same number of people are speeding even with the new lower speed limit, and the number of serious accidents are still dropping, then the lowering speed limit did not contribute to the reduction. Thats at least how I processed it. Would greatly appreciate if anyone could highlight my error.

Thank you.
Jonathan Evans
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Hi, jgabalski,

Good question. Let me start by addressing a slight issue in your analysis. The assumption here is that the lower speed limit led to lower speeds and fewer accidents, not less speeding (in the legal sense).

For instance, if the speed limit had been 40 mph and 50% of drivers people routinely traveled above 40 mph, the percentage of drivers "speeding" would be 50%. Now if the speed limit were lowered to 30 and 50% of drivers drive above 30 mph, the percentage of speeders has remained the same, even though in the latter case the actual speeds of the speeders might be lower.

This is the problem with answer choice (A): it leaves open the possibility that speeding still occurs on this street. For all we know, the percentage of "speeders" might even have increased concurrent with an overall decrease in average speeds.

Further, there are other considerations involved with speeding tickets. For instance, it is quite possible that police officers increased patrols at the same time as the speed limit was reduced, thus increasing numbers of tickets issued proportionate to the actual number of people committing the offense.

Long story short, lots of issues with (A). I hope this helps!
bk1111
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Hi - I picked E instead of C. I thought C would be committing a # v. % fallacy because the stimulus talks about accidents 35 percent lower than the # of serious accidents and C refers to the annual number. Can someone explain why C is correct despite this? And how can I avoid making this type of mistake in the future?

I have reviewed the chapter on #/% many times, but I still seem to get caught up in ?s involving this fallacy
AthenaDalton
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Hi bk1111,

This argument uses causal reasoning, that reducing the speed limit (cause) resulted in fewer accidents (effect). Answer choice (C) weakens the causal reasoning by offering an alternate explanation for the decrease in accidents: the cause wasn't the reduction in the speed limit but instead a reduction in the number of cars on the road. With fewer cars on the road, there will naturally be fewer accidents:

1981-1985: average of 100,000 cars on the road annually/ 100 serious accidents

1986-1990: average of 65,000 cars on the road annually / 65 serious accidents

The fact that (C) mentions an annual time period doesn't automatically discount it. Answer choice (C) states that there was an annual decline in the number of vehicles on the road over the course of an entire decade (1981-1990). So even though the word "annual" is used, this answer choice is really referring to the same span of years as the stimulus.

I hope this makes sense. Good luck studying!

Athena Dalton
brcibake
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I picked D because that attacks the claim that the cause for the reduction in incidents couldn't have been due to speed. How is this incorrect?
Thank you
Eric Ockert
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Hi!

Answer choice (D) would ultimately qualify as a Shell Game answer. The stimulus concludes that the reduction in the speed limit led to a decrease in serious. So even if answer choice (D) is true, and the number of non-serious accidents remained unchanged over this period, we still know from the stimulus that the number of serious accidents went up. Answer (D) doesn't make it any less likely that the reduction in speed limit was the cause of that increase.
Eric Ockert
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akanshalsat
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Hello!

I'm so so so so so confused as to why E is wrong. If E were true then wouldn't it weaken the argument bc perhaps 1986 and on "serious" accidents did not mean only if they resulted in extended hospital stay, but also if they were hospitalized at all - which is why there was a decrease in the percentages of "serious accidents" from 1986-90, bc the def. changed? I'm getting confused even writing it out.

I sort of understand why C is correct, but if it decreased steadily are the chunks from 86-90 (ratio wise) as different from 81-85?