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The city’s center for disease control reports that the rabies epidemic is more serious now than it was two years ago: two years ago less than 25 percent of the local raccoon population was infected, whereas today the infection has spread to more than 50 percent of the raccoon population. ████████ ███ █████████ ███████ ████ ███████ ███ █████ ███ ██ █████ ██ █████ ████████ ████ █████████ ██████ █ ████████ ███████ ██ ███ ████ ██ ██████ ████ ██ █████ ██ █████ ████████ ████ ██████████
Objective: Resolve a Discrepancy
The stimulus tells us about a rabies outbreak among raccoons in a particular city. According to the local center for disease control, a majority of raccoons are now infected, whereas two years ago fewer than a quarter were infected. This shows that the outbreak has worsened. However, according to the news, there were only 18 confirmed cases of rabid raccoons this year, whereas two years ago there were 32 confirmed cases.
This is where the apparent discrepancy comes from: how can a larger percentage, but a smaller number of raccoons have rabies now compared with two years ago? The best explanation for this "discrepancy" is that the raccoon population has decreased since two years ago. That way, fewer raccoons can represent a greater proportion of the overall population.
1.
Which one of the following, ██ █████ ████ █████ ██ ███████ ███ ████████ ███████████ ███████ ███ ███ ████████
a
The number of █████ ██ ██████ ██ ████ ███████ █████ ████ ████████ ███ █████████ ██ ███ ████ ██ ███████
(A) is a trap answer trading on the idea of the rabies epidemic getting
Rabies numbers in other animals don't explain how a greater proportion, but smaller number of raccoons have rabies now compared with two years ago. (A) still leaves us with a seeming discrepancy in raccoon rabies statistics.
b
A significant proportion ██ ███ ███████ ██████████ █████████ ██ ██████ ██ ███ ████ ██████ █████
A decrease in the overall raccoon population explains how a smaller number of raccoons can have rabies compared with two years ago, even though a higher proportion of raccoons are infected. If the population shrank significantly, it makes sense that fewer raccoons represent more of the raccoon population now. (B) resolves the seeming discrepancy.
c
The symptoms of ██████████ ███████ ███████ ██ █████ ████████ ███ ████████████ ███ █████████ █████████ ██ █████ ██ ███████
(C) tries to trick us into contradicting the stimulus, which is pretty definite that these statistics reflect actually rabid raccoons. The center for disease control talks about raccoons that are infected, not those that seem to be infected. And the newspaper mentions confirmed cases, not apparent cases.
With this in mind, the claim that distemper looks similar to rabies doesn't help to resolve the apparent discrepancy. We know for a fact we're dealing with rabies, so we still need to explain how there are fewer rabid raccoons, but a higher proportion of rabid raccoons.
d
Since the outbreak ██ ███ █████████ █████████ █████ ███ ████████ ██████████ ████ ████████████ ████ ████ ██████ ████████ ██████
(D) doesn't address the issue of proportions versus numbers which is raised by the stimulus. We're trying to explain how it can be that a much higher proportion of raccoons now have rabies, despite fewer individual raccoons being infected. Strange behavior in raccoons doesn't resolve that.
e
The number of █████████ █████ ██ █████ ████████ ██ ███████████ ██████ ███ ████ █████████ ████ ███ ████ █████
At best, (E) just tells us the same confusing result is happening in other cities—and that's only if we assume these cities also have a higher proportion of rabid raccoons than they used to. What (E) doesn't do is explain how this result could be happening; it doesn't resolve the discrepancy.