Politician: All nations that place a high tax on income produce thereby a negative incentive for technological innovation, and all nations in which technological innovation is hampered inevitably fall behind in the international arms race. Those nations that, through historical accident or the foolishness of their political leadership, wind up in a strategically disadvantageous position are destined to lose their voice in world affairs. So if a nation wants to maintain its value system and way of life, it must not allow its highest tax bracket to exceed 30 percent of income.

Summarize Argument
The politician concludes that nations should tax income only at rates lower than 30 percent in order to maintain their value system and way of life. For support, he cites a general rule: a high income tax produces a negative incentive for innovation, which causes a country to fall behind in the arms race. This causes those nations to lose international power, a circumstance threatening their values and way of life.

Notable Assumptions
The politician makes many assumptions. He assumes an income tax bracket exceeding 30 percent is high enough to produce a negative incentive for innovation, that such an incentive always hampers innovation, that falling behind in the arms race means suffering a “strategically disadvantageous position,” and that a nation that loses power internationally is at risk of compromising its way of life and values.

A
The top level of taxation must reach 45 percent before taxation begins to deter inventors and industrialists from introducing new technologies and industries.
This disputes the assumption that any income tax bracket exceeding 30 percent is high enough to create a negative incentive for technological innovation.
B
Making a great deal of money is an insignificant factor in driving technological innovation.
This calls into question the general rule, critical to the politician’s argument, that a high income tax produces a negative incentive for innovation.
C
Falling behind in the international arms race does not necessarily lead to a strategically less advantageous position.
This refutes the assumption that nations who lag in the arms race must be strategically disadvantaged, and thus breaks a link in the politician’s chain of reasoning.
D
Those nations that lose influence in the world community do not necessarily suffer from a threat to their value system or way of life.
This disputes the assumption that nations that lose international power risk compromising their values or way of life, breaking a link in the politician’s chain of reasoning.
E
Allowing one’s country to lose its technological edge, especially as concerns weaponry, would be foolish rather than merely a historical accident.
This is consistent with the politician’s statements because he says that falling behind in the arms race will cause a country to lose its international power, even if it’s due to foolishness.

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Expert witness: Ten times, and in controlled circumstances, a single drop of the defendant’s blood was allowed to fall onto the fabric. And in all ten cases, the stained area was much less than the expected 9.5 cm2. In fact, the stained area was always between 4.5 and 4.8 cm2. I conclude that a single drop of the defendant’s blood stains much less than 9.5 cm2 of the fabric.

Summarize Argument: Phenomenon-Hypothesis

The expert witness presents the hypothesis that a single drop of the defendant’s blood stains much less than 9.5 cm2 of the fabric. This hypothesis is supported by an observation that, in each of ten controlled tests, a drop of the defendant’s blood stained a much smaller area—only 4.5 to 4.8 cm2.

Notable Assumptions

The expert witness assumes that the controlled conditions of the ten tests are relevantly similar to (presumably) the crime scene. In other words, the expert assumes that the defendant’s blood would not have stained a much larger area in different, more relevant conditions.

The expert also assumes that ten tests are a large enough sample size to know how much fabric will be stained by a drop of blood. In other words, the expert assumes that more tests would not have changed the results.

A
If similar results had been found after 100 test drops of the defendant’s blood, the evidence would be even stronger.

This does not weaken the expert’s argument. Just because the evidence would have been stronger with 100 tests, that doesn’t mean that ten tests were too few. This doesn’t undermine the adequacy of the expert’s observations.

B
Expert witnesses have sometimes been known to fudge their data to accord with the prosecution’s case.

This does not weaken the expert’s argument. Some experts sometimes fudging their data tells us nothing about this particular expert, nor the quality of the expert’s observations. Like (E), this is just a weak attempt at an ad hominem attack.

C
In an eleventh test drop of the defendant’s blood, the area stained was also less than 9.5 cm2—this time staining 9.3 cm2.

This weakens the expert’s argument because it suggests that the ten tests may not be a reliable sample of how much fabric the defendant’s blood stains. In other words, this undermines the expert’s assumption that ten tests are enough.

D
Another person’s blood was substituted, and in otherwise identical circumstances, stained between 9.8 and 10.6 cm2 of the fabric.

This does not weaken the expert’s argument, because the argument is only concerned with defendant’s blood behaves, not anyone else’s blood. If anything, this shows that the test is able to show if someone’s blood stains a larger area, and is therefore more reliable.

E
Not all expert witnesses are the authorities in their fields that they claim to be.

This does not weaken the expert’s argument. Like (B), this is an attempt at an ad hominem attack on the expert. However, just some experts not truly being authorities tells us nothing about this particular expert or this particular argument.


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Detective: Because the embezzler must have had specialized knowledge and access to internal financial records, we can presume that the embezzler worked for XYZ Corporation as either an accountant or an actuary. But an accountant would probably not make the kind of mistakes in ledger entries that led to the discovery of the embezzlement. Thus it is likely that the embezzler is one of the actuaries.

Summarize Argument
The author concludes that the embezzler is like one of the actuaries at XYZ Corporation. This is because the embezzler must have had specialized knowledge about financial records, and the author believes this proves the embezzler was either an accountant or an actuary at XYZ. And, the author believes the embezzler was unlikely to be an accountant, because the ledger mistakes that led to the discovery of the embezzlement probably wouldn’t have been made by an accountant.

Notable Assumptions
The author assumes that only accountants or actuaries at XYZ would have had the specialized knowledge necessary to do the embezzlement. The author also assumes that an actuary isn’t just as unlikely as an accountant is to make the kind of mistake that led to the discovery of the embezzlement.

A
The actuaries’ activities while working for XYZ Corporation were more closely scrutinized by supervisors than were the activities of the accountants.
This provides a reason to think actuaries are less likely than accountants are to have committed the embezzlement. If actuaries’ activities were more closely scrutinized, that suggests it was more difficult for them to cheat.
B
There is evidence of breaches in computer security at the time of the embezzlement that could have given persons outside of XYZ Corporation access to internal financial records.
This questions the assumption that only an actuary or accountant at XYZ could have had the specialized knowledge to commit the embezzlement. If someone outside XYZ could have had that knowledge, then the suspects don’t have to be limited in the way the author assumes.
C
XYZ Corporation employs eight accountants, whereas it has only two actuaries on its staff.
Maybe each accountant had only a 49% chance of making the mistake that led to the discovery. But if there are 8 accountants, collectively the chance of one of those accountants making the mistake might be higher than the chance one of the two actuaries made the mistake.
D
An independent report released before the crime took place concluded that XYZ Corporation was vulnerable to embezzlement.
This doesn’t provide any reason to think the embezzler isn’t one of the actuaries. (D) helps establish that XYZ was vulnerable to embezzlement, but doesn’t suggest anything about what kind of person could have been the embezzler. (Correct because this is an EXCEPT question.)
E
Certain security measures at XYZ Corporation made it more difficult for the actuaries to have access to internal financial records than for the accountants.
This provides a reason to think actuaries are less likely than accountants are to have committed the embezzlement.

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