LSAT 84, Logical Reasoning II, Q9, LSATHacks

LR Question 9 Explanation, by LSATHacks

QUESTION TEXT: Marketing agent: A survey of my business clients reveals…

QUESTION TYPE: Flawed Reasoning

CONCLUSION: 90% of the agent’s clients increased their profit at least tenfold last year.

REASONING: 90% of the profitable businesses made at least $100,000 in profit. None of them made more than $10,000 in any year before last year.

ANALYSIS: The important thing to catch here is the switch from “of those who made a profit last year” to just “90 percent of my business clients”. This is a part-to-whole flaw – the author assumes that this part of the group (the profitable businesses) is representative of the whole group.

Say the agent has 100 business clients, and 10 are profitable. 9 of those 10 made over $100,000 in profit, when in previous years they never made more than $10,000. Here, 90% of the profitable businesses increased profit tenfold, but that’s only 9% of the total businesses.

The correct answer will point out this flaw.

___________

1. It doesn’t matter if the businesses who made over $100,000 only made slightly over that amount. They still increased their profits at least tenfold.
2. The author doesn’t need to explain this. And this isn’t our flaw.
3. CORRECT. The author takes the statistics for their profitable clients and claims this is true of all their clients.
4. The author doesn’t talk about conditions for making a profit – they’re just telling us about their profitable clients.
5. The author never says all their clients made an annual profit of more than $10,000. You may have picked this because you noticed that the author was drawing their conclusion incorrectly, and if so you were on the right track – but this answer doesn’t attack the flaw correctly. Answer C is better.

Recap: The question begins with “Marketing agent: A survey of my business clients reveals”. It is a Flawed Reasoning question. Learn how to master LSAT Flaw questions on the LSAT Logical Reasoning question types page.

Hi, I'm Graeme Blake

Founder of LSAThacks; I scored a 177 on the LSAT.

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