Critical Reasoning

Vitamin XYZ has long been a favorite among health food enthusiasts. In a recent large study, those who took large amounts of vitamin XYZ daily for two years showed on average a 40 percent lower risk of heart disease than did members of a control groups. Researchers corrected for differences in relevant health habits, such as diet.
Which one of the following inference is most supported by the passage?
(A) Taking large amount of vitamins is probably worth risking the side effects.
(B) Those who take large doses of vitamin XYZ daily for the next two years will exhibit on average an increase in the likelihood of avoiding heart disease.
(C) Li, who has taken large amounts of vitamin XYZ daily for the past two years, has a 40 percent lower risk.
(D) Taking large amounts of vitamin XYZ daily over the course of one's adult life should be recommended to most adults.
(E) Health food enthusiasts are probably correct in believing that large daily doses of multiple vitamins promote good health.


I actually eliminated all options because I thought all were wrong and then I had to choose something so I chose D.
I eliminated B, since I don't think one can make predictions based on a study without falsely assuming that Conditions in the next 2 years will be same as the conditions in the last 2 years when the Study was conducted.

Any expert opinion?

imskpwr wrote:Vitamin XYZ has long been a favorite among health food enthusiasts. In a recent large study, those who took large amounts of vitamin XYZ daily for two years showed on average a 40 percent lower risk of heart disease than did members of a control groups. Researchers corrected for differences in relevant health habits, such as diet.
Which one of the following inference is most supported by the passage?
(A) Taking large amount of vitamins is probably worth risking the side effects.
(B) Those who take large doses of vitamin XYZ daily for the next two years will exhibit on average an increase in the likelihood of avoiding heart disease.
(C) Li, who has taken large amounts of vitamin XYZ daily for the past two years, has a 40 percent lower risk.
(D) Taking large amounts of vitamin XYZ daily over the course of one's adult life should be recommended to most adults.
(E) Health food enthusiasts are probably correct in believing that large daily doses of multiple vitamins promote good health.


I actually eliminated all options because I thought all were wrong and then I had to choose something so I chose D.
I eliminated B, since I don't think one can make predictions based on a study without falsely assuming that Conditions in the next 2 years will be same as the conditions in the last 2 years when the Study was conducted.

Any expert opinion?

They seem to be going for the following logic: If a study is well-conducted (in this case, large and adjusting for confounding variables), and the study reveals that a vitamin/drug has a robust, positive effect, it stands to reason that we can expect others to derive some positive effect, should they take that vitamin or drug. So I suspect the OA is B.

You're right that this doesn't have to be true. Sometimes a study will have what appears to be a decisive outcome, and it turns out that the results are not reproducible in future studies. So it doesn't feel quite as air-tight as official CR questions tend to be, but it doesn't strike me as totally unreasonable. Out of curiosity, is this an official GMAT question?

DavidG@VeritasPrep wrote:

imskpwr wrote:Vitamin XYZ has long been a favorite among health food enthusiasts. In a recent large study, those who took large amounts of vitamin XYZ daily for two years showed on average a 40 percent lower risk of heart disease than did members of a control groups. Researchers corrected for differences in relevant health habits, such as diet.
Which one of the following inference is most supported by the passage?
(A) Taking large amount of vitamins is probably worth risking the side effects.
(B) Those who take large doses of vitamin XYZ daily for the next two years will exhibit on average an increase in the likelihood of avoiding heart disease.
(C) Li, who has taken large amounts of vitamin XYZ daily for the past two years, has a 40 percent lower risk.
(D) Taking large amounts of vitamin XYZ daily over the course of one's adult life should be recommended to most adults.
(E) Health food enthusiasts are probably correct in believing that large daily doses of multiple vitamins promote good health.


I actually eliminated all options because I thought all were wrong and then I had to choose something so I chose D.
I eliminated B, since I don't think one can make predictions based on a study without falsely assuming that Conditions in the next 2 years will be same as the conditions in the last 2 years when the Study was conducted.

Any expert opinion?

They seem to be going for the following logic: If a study is well-conducted (in this case, large and adjusting for confounding variables), and the study reveals that a vitamin/drug has a robust, positive effect, it stands to reason that we can expect others to derive some positive effect, should they take that vitamin or drug. So I suspect the OA is B.

You're right that this doesn't have to be true. Sometimes a study will have what appears to be a decisive outcome, and it turns out that the results are not reproducible in future studies. So it doesn't feel quite as air-tight as official CR questions tend to be, but it doesn't strike me as totally unreasonable. Out of curiosity, is this an official GMAT question?

Source: LSAT.
Since the question is from LSAT and I believe inference questions are same in both LSAT and GMAT. So I used it.
Have you seen any similar GMAT-CR-inference question that does not seem air tight.