Historian: In a territorial dispute in the mid-1700's, Ulmia's navy sought to capture merchant shipping entering and leaving Crinica's ports...
GMAT Critical Reasoning : (CR) Questions
Historian: In a territorial dispute in the mid-1700's, Ulmia's navy sought to capture merchant shipping entering and leaving Crinica's ports for four years until the dispute was resolved in Ulmia's favor. It has been assumed that this blockade was crucial to the outcome, but quantitative data refute this assumption: analysis of shipping records shows that over the course of the blockade, only \(\frac{1}{6}\) merchant ships attempting to enter or leave Crinican ports were actually captured by Ulmia.
Which of the following, if true, most seriously undermines the historian's interpretation of the data?
Passage Analysis:
| Text from Passage | Analysis |
|---|---|
| In a territorial dispute in the mid-1700's, Ulmia's navy sought to capture merchant shipping entering and leaving Crinica's ports for four years until the dispute was resolved in Ulmia's favor. |
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| It has been assumed that this blockade was crucial to the outcome, but quantitative data refute this assumption |
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| analysis of shipping records shows that over the course of the blockade, only one in six merchant ships attempting to enter or leave Crinican ports were actually captured by Ulmia. |
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Argument Flow:
The historian starts with historical facts, then challenges a common assumption by presenting contradictory data. The argument flows from general context to specific evidence that questions the traditional explanation.
Main Conclusion:
The naval blockade was NOT crucial to Ulmia's victory in the territorial dispute, despite what people have always assumed.
Logical Structure:
The historian uses quantitative evidence (shipping capture rates) to challenge a widely-held belief. The logic is: if the blockade was truly crucial, we'd expect much higher capture rates than just \(\frac{1}{6}\) ships. Since most ships got through, the blockade couldn't have been the deciding factor in Ulmia's victory.
Prethinking:
Question type:
Weaken - We need to find information that reduces belief in the historian's conclusion that the blockade wasn't crucial to Ulmia's victory
Precision of Claims
The historian's argument relies on a quantitative claim (only \(\frac{1}{6}\) ships captured) to conclude the blockade wasn't effective. We need to question whether this low capture rate actually proves ineffectiveness
Strategy
The historian assumes that because only \(\frac{1}{6}\) ships were captured, the blockade couldn't have been crucial. To weaken this, we need scenarios showing that even with a low capture rate, the blockade could still have been highly effective and decisive. We should look for ways that capturing just \(\frac{1}{6}\) ships could still devastate Crinica's economy or military capabilities
This tells us Crinica couldn't prevent the blockade, but this doesn't undermine the historian's interpretation about effectiveness. The historian isn't arguing about Crinica's defensive capabilities - they're arguing that the low capture rate (\(\frac{1}{6}\)) proves the blockade wasn't crucial. Whether Crinica could prevent it or not doesn't change the fact that most ships still got through.
Knowing that most ships were owned by Crinicans doesn't weaken the historian's argument. The historian's point is that only \(\frac{1}{6}\) ships were captured regardless of who owned them. Ship ownership doesn't change the capture rate data or make the blockade more effective than the numbers suggest.
Information about Crinica's trade patterns with Ulmia before the blockade doesn't address the historian's core argument. The historian is saying the blockade wasn't effective because the capture rate was low. Previous trade relationships don't change the fact that \(\frac{5}{6}\) ships were getting through during the blockade.
What happened to Ulmia's trade with other countries is irrelevant to whether the blockade of Crinica was effective. The historian's argument focuses specifically on the Crinica blockade's capture rates. Ulmia's other trade activities don't impact the interpretation of the \(\frac{1}{6}\) capture statistic.
This seriously undermines the historian's interpretation because it reveals that the \(\frac{1}{6}\) average is misleading. If captures increased sharply in the latter stages when Ulmia expanded its blockade force, then the blockade became much more effective toward the end of the dispute. This timing correlation suggests the enhanced blockade could have been the decisive factor in Ulmia's victory, even though the overall 4-year average was low. The historian assumed a consistent capture rate, but this shows the blockade's effectiveness varied significantly over time.