strengthening cr

This topic has expert replies
Master | Next Rank: 500 Posts
Posts: 185
Joined: Thu Feb 04, 2010 3:06 am
Thanked: 6 times

strengthening cr

by gmatnmein2010 » Fri Feb 05, 2010 11:37 pm
In prenatal testing for spina bifida, a life threatening disease, a false positive result indicates that an fetus has spina bifida when, in fact, it does not; a false negative result indicates that a fetus does not have spina bifida when, in fact, it does. To detect spina bifida most accurately, physicians should use the laboratory test that has the lowest proportion of false positive results.

Which of the following, if true, gives the most support to the recommendation above?

A. All laboratory tests to detect spina bifida have the same proportion of false negative results.
B. The laboratory test that has the lowest proportions of false positive results causes the same minor side effects as do the other laboratory tests used to detect spina bifida.
C. In treating spina bifida patients, it is essential to begin treatment as early as possible, since even a week of delay can result in loss of life.
D. The proportion of inconclusive test results is equal for all laboratory tests used to detect spina bifida.
E. The accepted treatment for spina bifida does not have damaging side effects.
Source: — Critical Reasoning |

User avatar
Legendary Member
Posts: 777
Joined: Fri Jan 01, 2010 4:02 am
Location: Mumbai, India
Thanked: 117 times
Followed by:47 members

by komal » Sat Feb 06, 2010 12:47 am
gmatnmein2010 wrote:In prenatal testing for spina bifida, a life threatening disease, a false positive result indicates that an fetus has spina bifida when, in fact, it does not; a false negative result indicates that a fetus does not have spina bifida when, in fact, it does. To detect spina bifida most accurately, physicians should use the laboratory test that has the lowest proportion of false positive results.

Which of the following, if true, gives the most support to the recommendation above?

A. All laboratory tests to detect spina bifida have the same proportion of false negative results.
Correct : If False negatives is the same, and you want the most accurate test, you obviously want to minimize False Positive... otherwise it could be the case that the test with the lower False positive rate has a higher False negative rate (which could neutralize or cancel out the lower False positive benefits).

B. The laboratory test that has the lowest proportions of false positive results causes the same minor side effects as do the other laboratory tests used to detect spina bifida.
Incorrect : Minor side effects is not the issue here.

C. In treating spina bifida patients, it is essential to begin treatment as early as possible, since even a week of delay can result in loss of life.
Incorrect : Treatment is not the issue here... diagnoses is the issue here.

D. The proportion of inconclusive test results is equal for all laboratory tests used to detect spina bifida.
Incorrect : This suggests that accuracy of the tests is equal for all laboratories. Ruled out.

E. The accepted treatment for spina bifida does not have damaging side effects.
Incorrect : Treatment/Side Effects is not an issue here. Eliminated
Hope this helps : )