Logical reasoning PrepTest 133 · Section 3 · Question 21

Incorrect. The premises and conclusion are both about a specific weed-killer, and it establishes that one form of it is effective while the other isn't. Establishing that that's common with weed-killers doesn't help the argument since it's already been established as true for this weed-killer.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen

Stimulus Summary:
A weed-killer has two mirror molecules, only one of which kills plants. Different soil causes a different one of the molecules to break down faster. So the data on the effects of the weed-killer are misleading.

Answer Anticipation:
The conclusion of this argument is that the data on the effects of a weed-killer is misleading. Why is that the case? Because it has different effects in different soil, and thus looking at the results of the weed-killer in one location wouldn't necessarily tell you anything about the effects in another.

However, it's possible that the data could control for that! If the weed-killer was tested in a variety of locations, the data could relate the local soil conditions to the effectiveness of the weed-killer.

The argument relies on that not being the case, and thus the data being misleading, so any answer that suggests the weed-killer wasn't tested in a variety of soil conditions, or the data doesn't tie the effectiveness to soil conditions, will be correct.

Answer Explanation:
This answer highlights that the data comes from a situation that's different from the real world, thus suggesting that the data won't reflect the real impact of the weed-killer, strengthening the argument.

Key Takeaway:
Don't let the science get in your way here! Start with the conclusion, which doesn't require any scientific knowledge—something is wrong/misleading. Work backwards to determine why the author believes that conclusion to be true—it'll have to do with the logic of the argument, not the underlying science.

Incorrect. While this answer suggests that data on the weed-killers effectiveness in these soil conditions would be widely useful, it doesn't establish that the existing data tested the weed-killer in soil matching those conditions. If it didn't, then the data would be very misleading to that group.

Incorrect. Remember—the Chemist's conclusion is that the data is misleading. This answer would strengthen the relevance of the data, and thus weaken the Chemist's argument. Since it's the Chemist's argument we're tasked with strengthening, this answer is wrong.

Incorrect. Without knowing if the data did rely solely on the examination of the effects of only one of the two forms, we can't know if this justifies the conclusion that the data is misleading.