A year ago the government

Answer choices

1. A

   Opposite4% picked this

   highway traffic has not increased over the

   When we see a Necessary Assumption answer choice ruling out a possibility with "not", we get very intrigued. We want to negate it and see if it weakens the argument. Would this negation hurt the argument? Highway traffic has increased over the past year. No that would strengthen the argument. If we have fewer fatalities even though there's more highway traffic, it sounds like something has really helped cut down on fatalities in the past year! (hint-hint: new speed limit) We could also say that this negation would strengthen the argument because it rules out the possibility that fatalities are lower this year because highway traffic is lower. This answer would be correct if it said, "highway traffic has not significantly decreased over the past year"

   4%
2. B

   Too Strong: most / obeyed21% picked this

   the majority of drivers obeyed the new

   In 99% of cases, the word/concept of "most" will be wrong on Necessary Assumption. When you negate that idea, you go from 51% to 49%. Does it badly weaken this argument if 49%, rather than 51%, of drivers obeyed the new speed limit? Of course not. The author's explanation definitely assumes that "a significant number of drivers have changed their driving speed in reaction to the new speed limit", because if almost no one changed their driving in reaction to the new speed limit, then we couldn't say that the new speed limit explains the drop in highway fatalities. But this answer is formulated way too strongly and specifically.

   21%
3. C

   Out of Scope: number of accidents23% picked this

   there is a relation between driving speed and the number of

   Very close, but the author is assuming there's a relationship between speed limit and the rate of highway fatalities. If we say there's no relation between speed and number of accidents, we're saying, "People drive like jerks and there's gonna be ~10,000 accidents a year no matter what". But that doesn't badly weaken the author's argument. She can still believe that by lowering the speed limit and thus (she assumes) lowering the average driving speed of cars, that same number of accidents could result in significantly fewer fatalities.

   23%
4. D

   Unnecessary Comparison: more strictly8% picked this

   the new speed limit was more strictly enforced than

   The author does not need the new one to be more strictly enforced than the old one. If the old one was strictly enforced, then the new speed limit could be just as strictly enforced and the argument would be fine. The author is assuming that the new posted speed limit is the causal difference-maker. She's not assuming that an increase in police presence is the causal difference-maker.

   8%
5. E

   Correct44% picked this

   the number of traffic fatalities the year before the new speed limit was introduced was

   Why this is right

   When we see a Necessary Assumption answer choice ruling out a possibility with "not", we get very intrigued. We want to negate it and see if it weakens the argument. Would this negation hurt the argument? the number of fatalities the previous year was abnormally high Yes, that provides the alternate explanation we were suspecting. This is just an alternate explanation that people don't see much: regression to the mean ... a return to normalcy. Consider this analogy: Our flower shop's revenue was down 45% this month compared to last. At the beginning of this month, we changed the sign on our window, so apparently new signage on your storefront can reduce store revenue. If we objected, "Yo ... this month is March. Last month was February, aka Valentine's Month, aka a month of abnormally high revenue for a flower shop. Obviously March is going to be 45% lower than February. That's because March is a normal month, and the previous month was just an outlier. We don't need to blame this on the new sign. We can just attribute this to a return to our normal baseline revenue." This answer rules out an alternate explanation for the curious fact. Fatalities aren't necessarily down this year because we did something new. we would have expected them to be down even if we had done nothing new, since last month was the outlier / the aberration / the funky thing that needs to be explained. Normalcy doesn't need an explanation. Deviations from normalcy do.

   Skill tested: Flaw · how this choice captures the argument's function is the move to repeat next time.

   44%