Summary
The level and rate of growth of aggregate output are the most significant indicators of the viability of a nation’s economy. Unemployment and inflation rates are also important indicators. Some countries have viable economies even though they do not have very large populations. For example, Switzerland and Austria have viable economies, but only about seven million people. Israel, Ireland, Denmark, and Finland all have viable economies, but less than seven million people.
Strongly Supported Conclusions
Having a very large population isn’t required to have a viable economy.
If the size of a country’s population is an indicator of the viability of a nation’s economy, it is not the most significant indicator.
If the size of a country’s population is an indicator of the viability of a nation’s economy, it is not the most significant indicator.
A
A nation’s economic viability is independent of the size of its population.
Unsupported. Although having a very large population isn’t required for a viable economy, that doesn’t imply that population size is completely independent of the viability of an economy. Maybe a population of one million, for example, is required for viability.
B
Having a population larger than seven million ensures that a nation will be economically viable.
Unsupported. We don’t have any evidence that every nation with more than seven million people is economically viable.
C
Economic viability does not require a population of at least seven million.
Strongly supported. We have several examples of countries with populations smaller than seven million that are nonetheless still economically viable.
D
A nation’s population is the most significant contributor to the level and rate of growth of aggregate output.
Unsupported. We are not told what are the most important contributors to the level and rate of growth of aggregate output.
E
A nation’s population affects the level and rate of growth of aggregate output more than it affects unemployment and inflation rates.
Unsupported. We do not have any evidence that a nation’s population affects aggregate output, unemployment, or inflation rates.
Summarize Argument: Phenomenon-Hypothesis
The author hypothesizes that susnpot activity is probably a causal factor in the size of hare populations. This is because the hare population cycle between larger and smaller sizes is correlated with the regular cycle of sunspot activity.
Notable Assumptions
The author assumes that the correlation between sunspot activity and hare population cycles isn’t just coincidence.
A
Reproduction in predator populations increases when sunspot activity indirectly affects hormonal processes associated with reproduction.
This strengthens by providing a potential causal mechanism between sunspots and hare populations. The sunspots might affect predator populations, and the predator populations would in turn affect hare populations.
B
Local weather patterns that can affect species’ population changes can occur both in the presence of sunspot activity and in its absence.
This doesn’t strengthen because it doesn’t provide any reason to think the sunspot activity has any causal relationship with hare populations. We have no reason to think these weather patterns are correlated with sunspots.
C
Brighter light during sunspot activity subtly but significantly improves the ability of predators to detect and capture hares.
This strengthens by providing a causal mechanism between sunspots and hare populations. The sunspots can affect predator ability to hunt, which in turn affects hare populations.
D
The variation from cycle to cycle in the magnitude of the highs and lows in snowshoe hare populations is highly correlated with variations from cycle to cycle in the intensity of highs and lows in sunspot activity.
This strengthens by strengthening the correlation between sunspots and hare populations. Not only are these two things generally correlated, but (D) now tells us that the specific degree of population increase/decrease is correlated with the degree of sunspot intensity.
E
Sunspot activity is correlated with increases and decreases in the nutritional value of vegetation eaten by the hares.
This strengthens by providing a potential causal mechanism. Sunspots may have an effect on the nutritional value of vegetation, which in turn can affect hare populations that eat the vegetation.
Summarize Argument: Counter-Position
Some advertising for heartburn medications is false because unrelieved heartburn is not likely to cause esophageal cancer. In reality, only about 5 percent of people with severe heartburn have a condition that raises the risk of cancer. So, only about 5 percent of people—those with this condition—are at a higher risk of developing cancer due to heartburn.
Identify Conclusion
The conclusion is the author’s contention that some heartburn medications are falsely advertised because it is not true that unrelieved heartburn is likely to cause esophageal cancer.
A
Only those people with Barrett’s esophagus can suffer an increased risk of developing cancer from heartburn.
This is a premise. The stimulus notes that only 5% of people—those with Barrett's esophagus—have a higher risk of cancer to support the conclusion that heartburn isn’t "likely" to increase the risk of cancer. If only 5% of people are at risk, it’s unlikely for the average person.
B
An increase in the risk of esophageal cancer arises from cells similar to those in the stomach’s lining developing in the lower esophagus.
This is a premise. It provides background on a condition called Barrett's esophagus, which the author mentions to support her conclusion. Since readers may be unfamiliar with Barrett’s esophagus, this claim gives them the information needed to follow the author’s argument.
C
Unrelieved heartburn is not likely to cause esophageal cancer.
This accurately states the main conclusion. The author argues that some heartburn-medication ads are untrue because unrelieved heartburn is not likely to cause esophageal cancer. Since only 5% of people are at risk, the average person is not "likely" to have an increased risk.
D
Some heartburn-medication advertisements imply that unrelieved heartburn is likely to cause esophageal cancer.
This is context. The claim that some heartburn-medication ads imply unrelieved heartburn is likely to cause esophageal cancer helps explain the author's argument, which concludes that this advertising is false since heartburn only increases cancer risk in about 5% of people.
E
The dangers touted by heartburn-medication advertisements will affect relatively few of the people who see those advertisements.
The stimulus doesn’t make this claim. A premise states that only 5% of people will have a higher risk of esophageal cancer from heartburn but doesn’t suggest that only 5% of people who see the ads have this condition. People with the condition may be more likely to see the ads.
Summarize Argument
The author concludes that watching too much TV leads people to overestimate risks. Her evidence is a study showing a positive correlation between people who watch more TV than average and people who believe they’ll be victims of natural disasters.
Notable Assumptions
Based on a mere correlation, the author concludes that watching too much TV causes people to overestimate risks. She thus assumes the opposite isn’t true (i.e. worrying about risks causes people to watch more TV), or that overestimating risks and watching TV aren’t jointly caused by some third factor. She also assumes that people who believe they’ll be victims of natural disasters believe the same about other risks the world presents. For example, if these people were less inclined to believe they’ll be the victims of violent crime, then the study wouldn’t help the author’s argument.
A
Many people overestimate the dangers that the world poses to them, regardless of the amount of television they watch.
Even if most people overestimate risk, watching too much TV might still be something that leads people to overestimate risk.
B
A person is less likely to live in an area that is prone to natural disasters if that person watches an above-average amount of television than if that person watches a below-average amount of television.
This seems to strengthen the author’s argument. People who watch lots of TV are less likely than average to be at risk of suffering a natural disaster, yet they believe themselves to be more at risk than average.
C
People who watch a below-average amount of television tend to have a fairly accurate idea of the likelihood that they will be victims of a natural disaster.
We don’t care about people who don’t watch much TV. We already know they’re less likely than people who watch lots of TV to believe they’ll be the victims of natural disasters.
D
People who are well informed about the risks posed by natural disasters tend to have become well informed in some way other than by watching television.
We don’t care about people who accurately estimate the risk posed by natural disasters. We need to weaken the link between watching lots of TV and overestimating risk.
E
A person is more likely to watch an above-average amount of television if that person lives in an area that is prone to natural disasters than if that person lives in an area that is not.
People who watch lots of TV have good reason to worry about natural disasters: they’re more likely than most people to live in areas prone to natural disasters. Thus, they might not be overestimating the risk of natural disasters at all.