heh, "most strongly strengthens".
I don't love the wording of this problem. There's enough context here—especially with that "also", there (boldfaced)—to determine that
this and
this are two references to the same group of athletes. By using two different wordings for the same specific group, though, this problem violates GMAC's own conventions for CR problem writing. Not good. (When GMAC includes two references to the same specific detail in a CR problem, they're scrupulous about using the same words both times.)
In problems like this one—basically, statistics problems couched in very wordy words—it's alws a good idea to
extract the statistical findings from the paragraph in order to consider them more easily.
The statistical findings here are:
• Some sprinters left the club. Some others joined—more than the # who left.
• The NEW (just joined) sprinters are FASTER than the club average.
<— Isolating this fact makes it VERY plain that we DON'T yet have the corresponding fact about the group who left!Well yeah... let's go to the choices and look for that OTHER corresponding fact we want—Were the sprinters who LEFT the club SLOWER than average?
D says exactly this. Answer is D. Done and dusted.
.
BTW
This problem really needs work... There's also a second violation of GMAC's best practices here, in that the correct answer actually completes a
rigorous PROOF of the given conclusion.
That contradicts the wording of the question ("most strongly..."). GMAC doesn't write sloppy problems like this; if a problem's conclusion is rigorously proved, there will not be any hedging language like "best" or "most strongly" that's only sensible in arguments whose conclusion is NOT rigorously proved.