Q14 - The mayor boasts that

[aidanmenzul]

I understand the best answer is E and not A (which I put), but not sure what was supposed to tip me of on the correct answer.

[ManhattanPrepLSAT1]

Oh no! Classic mistake. You found an answer choice that is relevant and so it sounded good (and by good, I mean on topic). Answer choice (A) would actually undermine the author's claim that the reduction came from the redefinition of "top priority."

The question asks us to strengthen the conclusion. Since the conclusion is an explanation of an observed phenomenon and answer choice (A) provides an alternative explanation for why the average ambulance time was reduced, answer choice (A) would undermine the conclusion drawn.

If the number of heart attacks and strokes declined, that could be the explanation for why the average ambulance turnaround time was reduced, and so the assertion that it was due to a redefinition would be undermined. It's easy to get turned around on weakening and strengthening questions and choose an answer that does the opposite of what you're asked.

Does that help clear this up?

[aidanmenzul]

yes, I think was getting lazy with this question because it looks fairly obvious now. I have a bad habit of staring at answer choices and debating them rather than just going back to the stimulus to find the right answer.

[levine.jesse]

Its because we are assuming that there were enough gun shot wounds to effect the average?! These indirect, scale, math based questions are hard! Wouldn't any amount of gun shot wounds have effected the average?

[WaltGrace1983]

This is a strengthen the conclusion question. Sometimes these stimuli are characterized by not having an argument so much as a piece of information and a conclusion that isn't really based on much. Keep in mind that it may not be possible to force an argument when there is no argument to force.

"Top Priority" emergencies used to include gunshot wounds and electrocutions, the most time-consuming cases
+
Now "Top Priority" simply means heart attack and strokes
→
Reduction in ambulance turnaround time for "top-priority" cases happened merely because of a redefining of "top-priority."

This definitely seems to be an argument and so I am looking at the reasoning as well. It seems that the argument is assuming something about gunshot wounds and electrocutions. Perhaps the argument is assuming that there was a significant amount of gunshot wound and electrocution cases and, because there isn't such cases anymore, it would make sense that the reduction in turnaround time was because of redefining "top-priority."

Remember, we need to STRENGTHEN the idea that reduction was because of redefinition

(A) This is a tricky one because it is definitely relevant to the core (sometimes this is enough). However, it ultimately doesn't do much to the argument. We are trying to strengthen the idea that the reduction was because of redefinition. Just saying that the number of heart attacks and strokes declined doesn't do anything! The number doesn't matter because we are talking about the average turnaround time. There could only be one case this year where an ambulance is needed. It doesn't matter!

(B) Out of scope. This has no bearing on the conclusion. This doesn't help prove WHY the reduction happened.

(C) Out of scope. This has no bearing on the conclusion. Just because experts disagree doesn't help prove anything about WHY the reduction happened.

(D) This is very similar to (C) and is also out of scope for having no bearing on the conclusion. It simply doesn't help prove WHY the reduction happened.

(E) This is very similar to what I suspected and, like a good strengthener, hinges on the implicit assumption of the argument. The assumption was that the gunshot wound/electrocution cases mattered. (E) is saying that they indeed do because, after all, there were a LOT of cases last year that involved gunshot wounds and electrocution cases. If there were a LOT of cases last year that dealt with those, it is reasonable to assume that not having such cases in ambulance turnaround time this year would significantly decrease the total turnaround time averages.

These indirect, scale, math based questions are hard! Wouldn't any amount of gun shot wounds have effected the average?

This question actually isn't based on math at all. You could substitute "over half" with "about one-third" and still get a similar result. In fact, I would argue that you could go as small as saying "about 10% of last year's cases involved gunshot wounds and electrocutions." Why? Because it still shows that they were significant and that they could have affected the average in a big way. Remember that these are the most time-consuming cases around.

[coco.wu1993]

I did this one right, but I can hardly see how E matters for AVERAGE turnaround time. Can anyone help?

[tommywallach]

Hey Coco,

Remember, an average is a mathematical construct, found by taking the TOTAL TIME USED FOR ALL AMBULANCE EVENTS divided by the TOTAL NUMBER OF AMBULANCE EVENTS.

If we know that HALF of all the events were of the time-consuming variety, then it would make sense that if we cut out those time-consuming events, it would lower the average.

Think of it this way, if I took the average speed of a group of runners, then removed the 10 slowest runners from consideration, what would happen to the average? It would rise, because the slowest people wouldn't be counted anymore.

Hope that helps!

-t

[coco.wu1993]

Hey Coco,

Remember, an average is a mathematical construct, found by taking the TOTAL TIME USED FOR ALL AMBULANCE EVENTS divided by the TOTAL NUMBER OF AMBULANCE EVENTS.

If we know that HALF of all the events were of the time-consuming variety, then it would make sense that if we cut out those time-consuming events, it would lower the average.

Think of it this way, if I took the average speed of a group of runners, then removed the 10 slowest runners from consideration, what would happen to the average? It would rise, because the slowest people wouldn't be counted anymore.

Hope that helps!

-t

Thanks Tommy! Got it now. I missed the "most time-consuming" part

[imjeff21]

A) If the number of heart attacks and strokes, the least time-consuming cases (with regard to the four we know about) declined this year, then the average ambulance turnaround time should rise. Whenever the smallest values of a population are removed, the average of the population rises. So if the number of heart attacks and strokes declined, the average, essentially, should rise. But it didn't. The average turnaround time declined from the previous year.

This tells us something had to have happened with the other part of the population (i.e. the other part of the population no longer exists). The fact that "top priority" emergencies no longer include gunshot wounds and electrocutions is now a valid argument. The fact that the two least time-consuming cases declined in number of occurrences this year strengthens the argument. It helps to validate the reasoning that the reduction in average ambulance turnaround time was produced simply by excluding gunshot wounds and electrocutions in the new definition of "top priority."

If (A) said "the number of heart attacks and strokes increased this year," then we would expect the average to drop and it would effectively weaken the argument. If the average dropped because of an increase in occurrences of the lowest values in the population, then the Mayor's claim is no longer a misrepresentation. We can take his claim that the average ambulance turnaround time has been reduced this year at face-value. Subsequently, the author's conclusion would be weakened.

I can't see how (A) does not strengthen the argument.

What am I missing here?

-Jeff

[af10]

A) If the number of heart attacks and strokes, the least time-consuming cases (with regard to the four we know about) declined this year, then the average ambulance turnaround time should rise. Whenever the smallest values of a population are removed, the average of the population rises. So if the number of heart attacks and strokes declined, the average, essentially, should rise. But it didn't. The average turnaround time declined from the previous year.

This tells us something had to have happened with the other part of the population (i.e. the other part of the population no longer exists). The fact that "top priority" emergencies no longer include gunshot wounds and electrocutions is now a valid argument. The fact that the two least time-consuming cases declined in number of occurrences this year strengthens the argument. It helps to validate the reasoning that the reduction in average ambulance turnaround time was produced simply by excluding gunshot wounds and electrocutions in the new definition of "top priority."

If (A) said "the number of heart attacks and strokes increased this year," then we would expect the average to drop and it would effectively weaken the argument. If the average dropped because of an increase in occurrences of the lowest values in the population, then the Mayor's claim is no longer a misrepresentation. We can take his claim that the average ambulance turnaround time has been reduced this year at face-value. Subsequently, the author's conclusion would be weakened.

I can't see how (A) does not strengthen the argument.

What am I missing here?

-Jeff

Hey, you're missing one key thing, I think.

The last sentence says "Now they are limited strictly to heart attacks and strokes." That is, the current pool we are dealing with only consists of heart attacks and strokes.

As answer choice (A) says, the number of heart attacks and strokes declined this year, but this does nothing for us. You made the mistake of thinking the population in discussion (top priority emergencies) for this year still included gunshot wounds and electrocutions. But they don't, anymore.

[ottoman]

is D wrong because it is a premise booster?

[ohthatpatrick]

You could call it a Premise Booster, if you like. (I personally never use that term)

I mean, the glib answer is that (D) is wrong because it doesn't strengthen. In what sense would learning about how OTHER cities classify gunshot wounds / electrocutions help us determine whether THIS city's redefining led to a change in ambulance time?

If I told you that "last year's 'top priority' emergencies included volcano eruptions and alien spacecraft wrecks but THIS year's 'top priority' emergencies no longer include those types of emergencies", would you think "Wow, that's going to really alter the average ambulance response time!"

Probably not, because it's unlikely that at any point last year an ambulance had to respond to a volcano eruption or alien spacecraft wreck.

If those emergencies never occur, then it won't make any difference to our average ambulance time whether we include those emergencies as "top priority" or not.

Similarly, if we never dealt with a gunshot wound or electrocution last year, then dis-including those events from THIS year's 'top priority' list would have no effect on our ambulances' response time.

In order for excluding gun wounds and electrocutions to impact our time, it must be the case that last year we DID respond to some gun wounds and electrocutions.

(E) gives us that, and then some ....

[ZLG870]

After careful examination and consideration, I fully understand how this argument works and why A is a good weakener.
Premises: the AVERAGE ambulance turnaround time has been reduced this year for top-priority emergencies
Conclusion: top-priority emergencies are limited only to heart attacks and strokes (relatively fast) by leaving out gunshot wounds and electrocutions( relatively time-consuming)

Let me give an extreme exmaple to clarify this:
a. Suppose there are just 1 emergency case for heart attcks and strokes (cost 10 minutes) and 1 emergency case for gunshot woulds and eletrocutions ( cost 20 minutes). The average time is 15 minutes.
b.if the emergency case of the gunshot wounds and electrocutions are eliminated, the average time is 10 minutes. ,(the average ambulance time has been reduced; the underlying principle is consistent with the argument ).
c. if the emergency case of heart attacks and strokes are eliminated, the average time is 20 minutes. (the average ambulance time has been increased; the basic principle is consistent with A)

OK, let us make this into a more abstract language; when we remove a number below the average, the average increases. A When the number of heart attacks and strokes declined (just think that these amounts of time devoted, below average, are removed), the average ambulance time were likely to increase. This weaken the argument.
However, those more time-consuming cases (above the average time), like gunshot wounds and electrocutions, out of the scope, the average ambulance time will decrease. This is the argument.

E is right. But actually, a half of all cases are too many. Just one case is enough. I mean if there is just one case of gunshot woulds and electrocutions, eliminating this category will definetely reduce the average time if other circumstances are not changed.

I think this mathematical dynamics is really useful for the LSAT question talking about the average. Remove the category above the average, and the average will decrease; remove the category below the average, and the average will increase.

Hope this helps!!