on May 17, 2022
This is of utmost importance, as it relates directly to the heart of understanding the logical structure in conditional principles/rules.
Lsatmax explanation for eliminating E is:
"Incorrect. High fluoride is correlated with high sodium levels, not the other way around. This answer reverses the relationship."
I respectfully and humbly disagree with this explanation, for I do not see an illegal reversal in E.
The word "where" introduces a sufficient condition!
"Soil that contains high concentrations of sodium-bearing minerals also contains high concentrations of fluoride-bearing minerals."
The second/last sentence of the argument states:
"In a recent study, researchers found that when rainfall, concentrations of fluoride-bearing minerals, and other relevant variables are held constant, fluoride concentrations in groundwater are significantly higher in areas where the groundwater also contains a high concentration of sodium."
When we abstract the logic from answer-choice E and the last sentence of the argument, we do not see an illegal reversal.
The issue with E, in my humble opinion, is that fluoride-bearing minerals are distinct from fluoride, and sodium-bearing minerals are also not the same as sodium.
In other words, the argument's last sentence draws a conditional rule between fluoride concentrations and sodium, whereas E draws a logically matching structure BUT between the "sodium-bearing minerals" and the fluoride-bearing minerals."
In retrospect, based on the argument, we can infer that a groundwater that contains a high concentration of sodium guarantees (or is sufficient to guarantee) significantly higher concentrations of fluoride in that very groundwater (the higher concentrations of fluoride in the same groundwater is the necessary part).
The flaw in E --"Soil that contains high concentrations of sodium-bearing minerals also contains high concentrations of fluoride-bearing minerals." -- is not that it commits an illegal reversal between the fluoride and the sodium.
The flaw is that E's sufficient part is "Solid that contains high concentrations of sodium-bearing minerals," and its necessary condition is "soil that contains high concentrations of fluoride-bearing minerals." And fluoride-bearing minerals and fluoride are not the same, and sodium-bearing minerals are also not the same as sodium.
Please let me know if I am wrong?
Already have an account?
on May 17, 2022
on May 21, 2022