#16 - The advanced technology of ski boots and bindings has

[Administrator]

Complete Question Explanation

Must be True-#%. The correct answer choice is (E)

This stimulus consists of information, and has no stated conclusion. You should differentiate causal arguments from causal information. This stimulus starts with causal information, and does not make any causal arguments.

The number of "slope" injuries decreased from 9 to 3 per 1000 skiers, and as a result the percentage of non-slope injuries rose from 10% to 25% of total resort injuries.

You should focus on the relationship between those numbers, and not fall into the trap of assuming that increased alcohol consumption follows from the increase in the correlating non-slope injuries. Even though the non-slope percentage contribution rose, the total number of resort injuries, and the number of non-slope injuries, could have fallen.

The truth is that these percentages do not help you determine any numbers. The only conclusion you should draw is that since the percentage of injuries attributed to non-slope activities rose, the percentage of injuries attributed to slope activities must have fallen, because those classifications cover the entire resort.

Answer choice (A): Since this argument does not allow you to make any inferences about the actual number of injuries.

Answer choice (B): Since there could be fewer overall injuries, the overall alcohol consumption could have decreased as well.

Answer choice (C): Since the stimulus only related ski-boots and bindings to slope injuries, you cannot conclude that such equipment is related to non-slope injuries.

Answer choice (D): Since "ski-related injuries" includes both slope and non-slope injuries, the total number of ski-related injuries could continue to increase even if slope activities are made safer, so this choice is wrong. Furthermore, it is conceivable that there is a point beyond which equipment cannot improve safety. Generally you should not project trends into the future, unless the stimulus does so.

Answer choice (E): This is the correct answer choice. The only conclusion you can derive is that since the non-slope percentage increased, the slope percentage decreased.

[Johnclem]

Hello ,
After reading the above explanation I still have some questions in regards to this problem:

Q1: I realize that this is a fact set, but I see the first sentence as the conclusion. ( the ideas in the passage seem to support this sentence ) am I wrong ?

Q2: this problem took me long because with my initial reading, I wasn't sure if this is a causality problem or #%. Particularly, I was tempted with the " as a result " statement. I took this to mean that the drop on ski resorts has caused the increase in other premises. BUT then I came to my senses after reading the above explanation , that because no causality occurred in the conclusion , then this can't be a casual argument. Am I finally getting this ?

Q3: if answer choice A had stated " as the percentage of ski injuries that occur on the slope decreases , the percentage of injuries that occur on the premises of ski resorts increases" ( instead of saying numbers ) would it have been correct ?

1- 1950: 9/1000
1980: 3/1000

2- as a result the remainder of ski related injuries occurring on other premises (not ski slopes) has increase.

3- the incidence of these injuries increases with the amount of alcohol consumed per skier.

C: the advanced technology of ski boots has brought a dramatic drop in the incidence of injuries that occur on the slopes of ski resorts.

Thanks
-John

[Nikki Siclunov]

John,

Thanks for your questions.

Q1: I realize that this is a fact set, but I see the first sentence as the conclusion. ( the ideas in the passage seem to support this sentence ) am I wrong ?

I'm afraid you are. The first sentence contains an observation, which is neither explained nor supported by the remainder of the stimulus. The numerical decrease in ski-related injuries clarifies the observation that ski boot technology has been beneficial, but the stimulus as a whole is not meant to support this finding. There is no argument here: just a collection of facts. (Whether an argument is present or not is ultimately irrelevant to the determination of what must be true).

Q2: this problem took me long because with my initial reading, I wasn't sure if this is a causality problem or #%. Particularly, I was tempted with the " as a result " statement. I took this to mean that the drop on ski resorts has caused the increase in other premises. BUT then I came to my senses after reading the above explanation , that because no causality occurred in the conclusion , then this can't be a casual argument. Am I finally getting this ?

There are elements of causality here, but they aren't questionable, because the causal relationships are stated as facts. These relationships are clarified with numerical evidence.

I took this to mean that the drop on ski resorts has caused the increase in other premises.

Not quite sure what you mean by this. All we know is that the number of ski-related injuries fell, as a result of which the proportion of non-ski related injuries increased. This makes perfect sense.

Q3: if answer choice A had stated " as the percentage of ski injuries that occur on the slope decreases , the percentage of injuries that occur on the premises of ski resorts increases" ( instead of saying numbers ) would it have been correct ?

Yes, that is correct.

Hope this helps!

Thanks,

[LSATer]

Can you please explain to me how "the incidence" of something relates to percents and numbers? Is there a relationship? I thought that incidence is a percentage idea and so you can make an inference about percents knowing the "incidence" and that is what led me to choose B.

I hope that my question makes sense.

Thanks,

LSATer

[Francis O'Rourke]

Incidence can refer to a rate, and rates are always relative measurements. In this stimulus, we learn about two different incidences or rates:

1. The rate of injuries per skier
2. the rate of non-slop injuries per all injuries

Since we do not know the overall number of skiers in either 1950 or 1980, we cannot conclude that more or fewer people were injured on the slopes. If more people skied in 1950 than in 1980, there would have been a decrease in the overall number of ski slope injuries. If however many more people skied in 1980 than in 1950, the number would have gone up.

To explain this, imagine that 1 thousand people skied in 1950 and 1 million people skied in 1980. Taking the incidence reports from the stimulus, then only 9 people would have been injured in 1950. If the overall number of skiers increased to 1 million in 1980, and according to the stimulus 3 people per thousand were injured in 1980, then 3,000 people would have been injured in 1980.

The exact calculation is not necessary. What is important to remember is that we cannot conclude anything about the actual number of injuries if we only know the rates of injuries.

This still does not provide evidence for Choice (B). There is no information to support any conclusion about how much anyone drank.

[biskam]

E is correct because the classification of injuries is divided only in 2: slope and non-slope. Still struggling w #% questions so trying to play around w q to learn... if there were another classification of injury, say slope, non-slope, and let's say injuries that occur in the hotel, then we wouldn't be able to say that E is correct without knowing if hotel injuries went up, went down or remained constant, right?

[Eric Ockert]

Hi biskam!

That's right. Here, the two categories are logical opposites of each other. One is on the slopes of ski resorts, the other is NOT on the slopes, but still at ski resorts. That creates only two possibilities. You are either on the slopes or you aren't. So if the share of one category goes up, the other must go down, and vice versa. The two percentages would always add up to 100%.

You couldn't have "slope", "non-slope", and "hotel" as three separate categories though. "Hotel" would fall under "non-slope". You probably would need something like "slope", "hotel" and "lodge". While each of these may be exclusive of each other, there may be other possibilities as well. So an increase in the share of one does not necessarily prove what is happening elsewhere.

Hope that helps!

[sy7705]

Hello! I was just passing by and wondering if the term "incidence" in (C) refers to the absolute frequency of something happening, as opposed to its relative frequency (percentage, ratio, etc).

[James Finch]

Hi Sy,

Given that the stimulus uses "incidence" to mean proportionate rate, (C) would also be using incidence to mean a proportionate rate, rather than an absolute number. (C) isn't testing whether you identify the distinction between percentages and absolute numbers, but rather the whole-to-part fallacy (as reducing overall incidence of injuries doesn't necessarily mean a reduction in each and every category of them).

Hope this clears things up!

[thecmancan]

I learned here that

9 injuries in 1000 down to 3, really means 3 injuries in a 1000, not 3 total injuries.