Weaken

nimish_rulz · Posted: Tue Apr 01, 2008 9:36 am Post subject: Weaken

In the United States, of the people who moved from one state to another when they retired, the percentage who retired to Florida has decreased by three percentage points over the past ten years. Since many local businesses in Florida cater to retirees, this decline is likely to have a noticeably negative economic effect on these businesses.

Which of the following, if true, most seriously weakens the argument?

A. Florida attracts more people who move from one state to another when they retire than does any other state.
B. The number of people who move out of Florida to accept employment in other states has increased over the past ten years.
C. There are far more local businesses in Florida that cater to tourists than there are local businesses that cater to retirees.
D. The total number of people who retired and moved to another state for their retirement has increased significantly over the past ten years.
E. The number of people who left Florida when they retired to live in another state was greater last year than it was ten years ago.

I don't knw how to hide the answer but
The Official Answer according to the test is D but I feel it should be C. Any explanations?
The source of this 800 Tests

Stuart Kovinsky · Posted: Tue Apr 01, 2008 3:45 pm Post subject:

Here we have a classic scope shift which often appears in Critical Reasoning questions: percents to numbers.

The evidence is about the % of retirees who move to Florida. The conclusion is that, as a result of the % decrease, businesses will suffer.

However, whenever we see %s in CR arguments, we should always think "% of what?"

Just because % decreases, we don't necessarily know that numbers decrease. When we want to weaken a % to number scope shift, let's look for an answer choice that focuses on the actual numbers.

(D) does exactly that: If we know that the number of retirees who move has greatly increased, then the pie is much bigger. So, even though the % of the pie has decreased, the actual number of retirees moving to Florida may have increased, not decreased. Hence, things are looking up for Floridian restaurants that serve dinner at 4pm and sell shorts that go up to your chest!

(C) is outside the scope. The author's conclusion is only about businesses that cater to retirees ("these businesses"), so other busniesses are irrelevant.

nimish_rulz · Posted: Tue Apr 01, 2008 3:56 pm Post subject:

Thank you for clearing up my doubt.
Appreciate it.

chidcguy · Posted: Sun May 11, 2008 9:44 am Post subject:

I agree that we should be looking at what percent of. But the correct answer 'D' stops short of saying that the influx of retirees was into FL.

The total number of people who retired and moved to another state for their retirement has increased significantly over the past ten years.

Aren't we assuming more than what is stated in the correct answer choice. Are you saying that for percentage Q's the concept of what percent of whole trumps others and its a GMAT rule.

I felt like C was a little bit out of scope, but I felt like it was introducing evidence that weakens the conclusion. Most strengthen and weaken Q's does this. Not all the times, supporting evidence is entirely in scope. By scope, I mean any words (like tourists here) not mentioned in the original stimulus need not necessarily make it out of scope.

<rant> Its tough to get into the head of the test makers and think exactly like they think </rant>

All said, It appears to me that for percent CR Q's, the favorite answer seems to be in the part vs whole relationship.