Self-study
Support Whenever a company loses a major product-liability lawsuit, the value of the company's stocks falls significantly within hours after the announcement. █████ ███ ████ ████ ████████ ██ █ █████ █████████████████ ████████ ███ ███ ██████ ████ █████████████ ██ █████ ██████ ██████████ ██ ███ ██ ████ ████ ██ ███████████ ████████ ███████ █████ ██ ████ ███████ ███ █████████ ███████ ██████
Method of Reasoning
The author concludes that Cotoy must have lost a lawsuit. His reasoning is that Cotoy’s stock has fallen, and losing a lawsuit would cause their stock to fall.
Identify and Describe Flaw
This is the cookie-cutter flaw of confusing sufficiency and necessity. We are told that losing a lawsuit is sufficient to cause a company’s stock to drop. The author then erroneously infers that a company’s stock drop can only be caused by losing a lawsuit. (In other words, that losing a lawsuit is necessary for a company’s stock to drop.) But there could be any number of other reasons—e.g. the release of a competing product—why a company’s stock might drop.
Note that the context is that Cotoy was involved in a lawsuit, but the premise is that losing lawsuits causes a decrease in stock prices. Just because Cotoy was sued doesn’t mean it will lose the lawsuit.
17.
Which one of the following ████████ ██████ █████████ ████ ████ ███████ █████████ ████ ██ ███ ████████ ██████
a
Whenever a business ██████ ███ █████████ ███████████████ ███ █████████ █████ ██ ████ ██████████ ████████ █████ ██ ████ ███ ██ ███ ██████████ ██████████ ███ █████████ ████ █████ █████ █████████ ███████████████
This is the wrong flaw. (A) overlooks that Shopwell may want a certain outcome, but fail to obtain it. (I.e., it fails to show that its given conditional relationship applies.) By contrast, the stimulus confuses the necessary and sufficient conditions in a relationship.
b
Whenever the large ████████ ████████ ██████ ███ █████████ █████████ ██ ███████ █████████ ████████ ██ █████████ █████████ ██████████ ███ ███████ █████████ █████████ █████████ █████████ ████ ██ █████████ ██████████ ████ ███ █████ ████████ ████████ █ █████ █████ █████████
This is the wrong flaw. (B) tell us that a sufficient condition (decreased fares) triggers a necessary condition (decreased financial stability). But it fails to justify its assumption that increasing the sufficient condition will always increase the necessary condition. (For example, if you water a plant, it will grow, but watering it more doesn’t always cause it to grow more.) By contrast, the flaw in the stimulus is confusing necessary and sufficient conditions.
c
Whenever a country █████ █ ████ ██ ██████████ ██ █████████████ ███████ ███████ ███ ███ █████████ ████████ ██████ ██ ████████ ██████████ ██ ████ ███████ ███ ███ █████████ █ ███████ ██████ ████ ██████████ ██ █████████████ ███████
This is the wrong flaw. (C) takes a conditional relationship (if no leadership, then decreased respect) and assumes it’s still true if you negate both sides (if leadership, then increased respect). This is not a valid inference. By contrast, the flaw in the stimulus is confusing necessary and sufficient conditions.
d
Whenever an entering ███████ ██ ███████ ███████ ████ ███ ███████████ ███████████ ██ ██ ███ ████████ ████████ ██████████ █████ █ ███████ ███ ███ ████████ ██ ████████ ████ ████ ███ ███ ███████████ ███████████ ███████ ███ ████ ████████ ███████ ████ ███ ████████
(D) concludes that Eula must have won the Performance Fellowship. The reasoning is that Eula has received $10,000 from the college, and winners of the Fellowship receive $10,000 from the college.
This is the same cookie-cutter flaw of confusing necessary and sufficient conditions that we saw in the stimulus. Just because winning the fellowship leads to a prize of this sum doesn’t mean it’s the only time a prize of this sum is awarded.
e
Whenever a company ██████████ ███ ████████ ████████████ ███ █████████ █████ █████████ ███████ █████ ████ ███ ██████████ ██████████ ██ ██ ██████ ████ ███ ███████ ███ ███ █████████ ███ ████████ ████████████
This is a valid argument, unlike the stimulus. It correctly applies the contrapositive of the initial conditional statement.