## #8 - Travel writer: A vacationer should choose an airline

PowerScore Staff

Posts: 6670
Joined: Wed Feb 02, 2011 4:19 pm
Points: 3,343

Complete Question Explanation

Parallel Flaw-#%. The correct answer choice is (B)

The author of this stimulus mistakes an average occurrence with a solid number. An average likelihood is not affected by historical performance. Here is an old riddle: If you have tossed a coin 10 times and it has landed heads up each time, if your tosses are random, what are the odds that your next toss will land heads up? The chances are 50/50. Each new flip is subject to the overall average, and a heads-up flip last time tells us nothing about the prospects for the next random coin toss.

If planes have an accident once every five years on average, that is very different from each plane having exactly one accident in every five-year period. So it is invalid to assert that a plane that has had a recent crash is now safe for five years.

Answer choice (A): This answer choice does not reflect the logical flaw found in the stimulus; rather than dealing with statistical conclusions based on past performance, this answer choice concerns whether or not a coin is "fair."

Answer choice (B): This is the correct answer choice. Like the author in the stimulus, the author of this answer choice is under the mistaken impression that a baboon can get its bad luck "out of the way," and that past poor performance means greater chances of future positive performance. This is wrong. And, like the plane from the stimulus, the referenced baboon may likely have less chance of ascending if he has already proven unable to for many years.

Answer choice (C): This answer choice reflects a different type of logical flaw: the odds of the "average resident" getting into a traffic accident are not necessarily equal to the odds for any given individual. Since Marty doesn't drive, and may spend less time in cars than the "average citizen," the conclusion here is flawed, but in a different way from the stimulus author's conclusion.

Answer choice (D): The reasoning in this answer choice is valid, so this answer cannot possibly parallel the flawed reasoning found in the stimulus.

Answer choice (E): The flaw here is the presumption that the grandmaster's actions in this tournament will be unwavering, maintaining a perfect 90% likelihood of the referenced response. This logic is not valid, but because it is not the same type of flawed reasoning found in the stimulus, this answer choice is incorrect.