PrepTest 102

Incorrect. In this study, only one of twenty returns prepared by a pro was correct. However, there's no way to know that these results are representative, so this answer goes a step too far.

Correct. Argument or Facts:
Facts

Question Type:
Must Be True

Stimulus Summary:
Experiment - 20 income tax pros were given the same tax returns
Results - No two were the same, and only one was correct

Answer Anticipation:
This Must Be True question doesn't really suggest specific inferences, as it doesn't have statements that chain together or build off of each other. Instead, it gives the results of an experiment that was done.

As such, we should look for an answer that generalizes from those results without overstepping. We only have the results from a study of 20 income tax advisors, so we can't make any bold proclamations, but we can certainly support a weak generalization about what might or could be true.

In any case, we need to be precise with our understanding of the results, so with those in mind, let's head to the answer choices.

Answer Explanation:
In the experiment, 19 income tax pros did something wrong on the return they created. Even if these 19 are the only 19 in the world who would make mistakes, they still show that hiring a pro doesn't provide a guarantee, as you may have hired one of these 19. As such, this answer is supported. Note that it uses negated strong language ("no guarantee") to create a weak answer—rephrased, this answer says, "A professional income tax advisor might prepare your taxes wrong."

Key Takeaway:
When a Must Be True question describes a situation more than creates a series of statements that can be stitched together, correct answers tend to generalize from that situation. However, be careful of generalizations that are too strong or broad based on the stimulus. Here, the stimulus looked at only 20 pros, so we needed a weak generalization.

Additionally, negated strong language results in a weak answer choice. "No guarantee" means "may be wrong."

Incorrect. For this answer to be true, it would need to be the case that only pros could prepare a correct return. There's no indication, however, that non-professionals can't do so. (The fact that 19/20 pros got it wrong isn't a reason to rule this answer choice out, as it doesn't state that every pro would get it right, just that only pros can get it right.

Incorrect. In the experiment, one pro got the return right. That's no guarantee that she'd prepare all returns correctly, but we don't have any evidence that she wouldn't, so this answer is unsupported.

Incorrect. There's no discussion of how well the average person does at preparing their own taxes. And the professionals' success rate isn't all that high . . .