The violent crime rate (number of violent crimes per 1,000 residents) in Meadowbrook is 60 percent higher now than it was four years ago. The corresponding increase for Parkdale is only 10 percent. These figures support the conclusion that residents of Meadowbrook are more likely to become victims of violent crime than are residents of Parkdale.
The argument above is flawed because it fails to take into account
- A. changes in the population density of both Parkdale and Meadowbrook over the past four years
- B. how the rate of population growth in Meadowbrook over the past four years compares to the corresponding rate for Parkdale
- C. the ratio of violent to nonviolent crimes committed during the past four years in Meadowbrook and Parkdale
- D. the violent crime rates in Meadowbrook and Parkdale four years ago
- E. how Meadowbrook’s expenditures for crime prevention over the past four years compare to Parkdale’s expenditures
Solution
Passage Analysis:
| Text from Passage | Analysis |
|---|---|
| The violent crime rate (number of violent crimes per 1,000 residents) in Meadowbrook is 60 percent higher now than it was four years ago. | What it says: Meadowbrook’s violent crime rate jumped 60% over four years What it does: Establishes baseline data about crime trends in one location What it is: Statistical evidence Visualization: If Meadowbrook had 10 violent crimes per 1,000 residents four years ago ā now has 16 violent crimes per 1,000 residents |
| The corresponding increase for Parkdale is only 10 percent. | What it says: Parkdale’s violent crime rate only increased 10% in the same period What it does: Provides comparative data that makes Meadowbrook’s increase look much worse What it is: Comparative statistical evidence Visualization: If Parkdale had 10 violent crimes per 1,000 residents four years ago ā now has 11 violent crimes per 1,000 residents (vs. Meadowbrook’s 16) |
| These figures support the conclusion that residents of Meadowbrook are more likely to become victims of violent crime than are residents of Parkdale. | What it says: The author concludes Meadowbrook residents face higher crime risk than Parkdale residents What it does: Makes a logical leap from the rate changes to current absolute risk levels What it is: Author’s main conclusion |
Argument Flow:
The argument starts with crime rate increases for two cities over four years, then jumps to a conclusion about which city is more dangerous now. We go from “Meadowbrook’s rate increased more” to “Meadowbrook is more dangerous.”
Main Conclusion:
Residents of Meadowbrook are more likely to become victims of violent crime than residents of Parkdale.
Logical Structure:
The author uses the percentage increases in crime rates as evidence to support a claim about current relative safety. However, this creates a logical gap – we’re told about changes but not about the actual current crime rates in each city.
Prethinking:
Question type:
Misc – This is a flaw question asking what the argument fails to consider. We need to identify what important information is missing that makes the conclusion potentially incorrect.
Precision of Claims
The argument makes claims about percentage increases in crime rates over time (60% vs 10%) and concludes about current absolute risk levels. The precision issue is that percentage changes don’t tell us about actual current crime rates.
Strategy
For this flaw question, we need to think about what crucial information the argument ignores when jumping from percentage increases to absolute risk levels. The key flaw is likely about baseline rates – we can’t determine current risk just from knowing percentage changes without knowing what those percentages are applied to.
Answer Choices Explained
A. changes in the population density of both Parkdale and Meadowbrook over the past four years
Population density changes don’t directly affect our ability to compare crime rates, since crime rates are already calculated per 1,000 residents. The rate calculation inherently accounts for population, so density changes wouldn’t impact the validity of using these rates to compare safety levels between the cities.
B. how the rate of population growth in Meadowbrook over the past four years compares to the corresponding rate for Parkdale
Population growth rates are also irrelevant here because we’re dealing with crime rates (crimes per 1,000 residents), not absolute numbers of crimes. Whether a city’s population grew fast or slow doesn’t change the meaning of its crime rate or our ability to compare rates between cities.
C. the ratio of violent to nonviolent crimes committed during the past four years in Meadowbrook and Parkdale
The ratio of violent to nonviolent crimes is a red herring. The argument is specifically about violent crime rates only, and the conclusion is about violent crime victimization likelihood. Information about nonviolent crimes wouldn’t affect this analysis.
D. the violent crime rates in Meadowbrook and Parkdale four years ago
This hits the core flaw perfectly. We can’t determine which city is more dangerous today just from knowing percentage increases without knowing what those percentages started from. If Meadowbrook had a much lower baseline rate four years ago, it could still be safer than Parkdale now despite the larger percentage increase. The argument completely ignores these crucial starting points.
E. how Meadowbrook’s expenditures for crime prevention over the past four years compare to Parkdale’s expenditures
Crime prevention expenditures might be interesting context, but they don’t address the logical gap in the argument. The flaw isn’t about what might explain the trends – it’s about whether we can validly conclude current relative safety from the given percentage data alone.
