Logical Reasoning

PT125 · S2 · Q14 The number of serious

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The number of serious traffic accidents (accidents resulting in hospitalization or death) that occurred on Park Road from 1986 to 1990 was 35 percent lower than the number of serious accidents from 1981 to 1985.

Evidence

The number of serious traffic accidents that occurred on Park Road from 1986 to 1990 was 35 percent lower than the number of serious accidents from 1981 to 1985.

The speed limit on Park Road was lowered in 1986.

Conclusion (hence)

Hence, the reduction of the speed limit led to the decrease in serious accidents.

Evaluate

The evidence establishes a correlation between lowering the speed limit on Park Road in 1986 and a decreased number of serious accidents. But correlation does not prove causation, as the conclusion asserts.

14.

Which one of the following statements, if true, most weakens the argument?

  1. The number of speeding tickets

    Out of Scope

    The number of speeding tickets is a product of both the number of people who speed on Park Road and the level of enforcement on that road. It could be that the number of tickets remained constant even if the number of people who speed on Park Road decreased because the level of enforcement increased.

    6% picked this

  2. Beginning in 1986, police patrolled

    Strengthen

    This makes it more likely that the decrease in serious accidents was not from increased enforcement of the speed limit on Park Road.

    4% picked this

  3. Correct

    The annual number of vehicles

    Why this is right

    This weakens the argument by providing an alternative explanation for the reduced number of serious accidents after 1986.

    Skill tested: Weaken · how this choice captures the argument's function is the move to repeat next time.

    69% picked this

  4. The annual number of accidents

    Strengthen

    This makes it more likely that the reduction in serious accidents was not from a reduction in the number of drivers on the road. By undermining an alternative explanation, this makes the argument’s conclusion more likely to be true.

    2% picked this

  5. Until 1986 accidents were classified

    Strengthens, if anything

    This says that in 1986, the definition of "serious" accident was expanded to include any accident that had a hospital stay (not just those that had lengthy hospital stays). This would provide an explanation for why there would be more serious accidents from 1986 onward. Since we know that there were fewer serious accidents from 1986 onward, that means that something (maybe the new speed limit) is really making a big difference. So if anything, this could strengthen. If this said, "Beginning in 1986, accidents were only designated 'serious' when they resulted in a lengthy hospital stay", then it could be a correct answer. That would offer an alternate explanation for why the number of serious accidents dropped.

    19% picked this

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