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.
 
The best answer is A.    Only if all tests have the same proportion of false negative results does the one with the lowest proportion of false positives become the most accurate.

Health club membership has increased dramatically over the last five years.  In order to take advantage of this increase, Fitness Express plans to open more of the same types of classes available during the week, while continuing its already very extensive advertising in newspapers and on the radio.

Which of the following, if true, provides most support for the view that Fitness Express cannot increase membership to its gyms by adopting the plan outlined above?

A.  Although it fills all of the classes it opens, Fitness Express’s share of all health club memberships has declined over the last five years.

B. Fitness Express’ number of classes offered to their clients has declined slightly over the last year.

C.  Advertising has made the name of Fitness Express widely known, but few customers know that Fitness Express health clubs also off acupuncture and shiatsu treatments.

D. Fitness Express’s health clubs is one of three clubs that have together accounted for 88% of health club memberships.

E.  Despite a slight decline in membership price, sales of Fitness Express memberships have fallen in the last five years.  
 
The best answer is E.  According to the information is choice E, Fitness Express has already failed to participate in the industry trend of greater sales despite their advertising campaign.  Opening more of the same types of classes would therefore be unlikely to create more membership sales for Fitness Express.