Question

Difficulty: HardMost Strongly Supported Questions

A long-term study of commercial vineyards found that every vineyard that successfully eliminated powdery mildew over the last decade had implemented a high-density canopy management system. The study also showed that among the vineyards utilizing high-density canopy management, only those that simultaneously applied sulfur-based bio-fungicides experienced a measurable increase in overall grape yield. Furthermore, several vineyards applied sulfur-based bio-fungicides without implementing high-density canopy management; while these vineyards saw a measurable increase in overall grape yield, they failed to eliminate powdery mildew.

Statement: Based on the study, it is most strongly supported that the application of sulfur-based bio-fungicides is a sufficient condition for a vineyard to experience a measurable increase in overall grape yield.

Answer: Answer

Answer

False
The proposed inference incorrectly identifies a necessary condition and a partial observation as a universal sufficient condition. The stimulus states that among vineyards with high-density canopies, 'only those' with bio-fungicides increased yields (making the fungicide necessary, not sufficient). Furthermore, the observation that 'several' vineyards with fungicides but no canopy management also increased yields provides evidence for 'some', but fails to establish a universal guarantee. Therefore, the statement is logically unsupported.

Step-by-Step Solution

1
Analyze the conditional relationship between canopy management and eliminating mildew.
Eliminating powdery mildew requires high-density canopy management.
The text states that 'every vineyard that successfully eliminated powdery mildew... had implemented' the canopy system.
2
Analyze the conditional relationship between bio-fungicides, canopy management, and grape yield.
For vineyards with high-density canopies, increased yield requires sulfur-based bio-fungicides.
The text states 'among the vineyards utilizing [the canopy system], only those that simultaneously applied [bio-fungicides] experienced a measurable increase'.
3
Evaluate the evidence regarding vineyards with bio-fungicides but without canopy management.
Some (several) vineyards with bio-fungicides and without the canopy system experienced increased yields.
The text explicitly mentions 'several' such vineyards achieved this, establishing a 'some' statement rather than an 'all' statement.
4
Compare the synthesized logical rules against the proposed statement.
The statement incorrectly claims applying bio-fungicides is sufficient to guarantee increased yield.
The premises only establish bio-fungicides as a necessary condition in one specific context, and as being present in 'several' successful cases in another context. It is never established as a universal guarantee (sufficient condition).

Key Concept

Distinguishing between necessary conditions, sufficient conditions, and existential qualifiers ('some' vs. 'all') when evaluating logical inferences.
Estimated Time:1m 45s
Rate this question