PrepTest 129, Section 1, Question 3
On the first day of trout season a(59 more words not shown)
The reasoning above is most(8 more words not shown)
- Amakes a generalization(9 more words not shown)
- Brelies on evidence(6 more words not shown)
- Cignores the variations(11 more words not shown)
- Dfails to take(10 more words not shown)
- Edoes not consider(8 more words not shown)
Reading the argument
The anglers chose which fish to hand over. That is where I would pause.
Suppose an angler catches ten trout and proudly picks the two biggest for the biologists to weigh. Those two fish may be much heavier than the other eight. Or the angler might choose the two smallest. Either way, allowing people to select their fish gives us a reason to question whether the weighed fish represent the trout in the river.
We can accept that ninety fish were weighed accurately. The problem comes when the argument uses those measurements to announce the average weight of the river's trout. A substantial number of measurements won't fix a selection process that systematically favors unusual fish.
What we’re looking for
The flaw question should therefore point to the move from these selected fish to the larger population. We don't have to know that the anglers picked the biggest trout, or calculate the true average. We need to see why this method leaves the reported average doubtful.
Working the answers
- ACorrect
The argument generalizes from the selected ninety fish to trout throughout the Macawber River. Since the anglers chose which two fish to submit, the sample could favor especially large, impressive catches rather than typical trout. The measurements can be accurate while the conclusion about the river's average is inaccurate.
- B
These aren't merely anglers telling stories about how big their catches were. Biologists actually weighed the fish. Scientific measurement can still be undermined by an unrepresentative sample, but that doesn't turn the evidence into anecdotes. A identifies the problem with how the measured fish were selected.
- C
The conclusion concerns the beginning of this season, when the fish were weighed. Trout might gain or lose weight later without affecting an estimate restricted to the beginning. We don't need to object to changes over the entire season when the conclusion makes no claim about that whole period.
- D
Last year's trout could have been heavier or lighter. That wouldn't settle the average at the beginning of this season. The argument isn't comparing seasons or claiming the average never changes; it needs a representative sample of the current trout population.
- E
The anglers may have caught bass or other fish too, but the conclusion is about trout, and the described measurements concern the trout selected for weighing. The existence of other catches doesn't identify the gap between these selected trout and the trout population.
More Flaw questions
Learn the LSAT our way
Our platform drills Flaw questions at your level and adjusts as you improve.