Logical reasoning PrepTest 154 · Section 4 · Question 8

Incorrect. Way too strong. We don't have any premise that suggests this. This is an example of inferential overreach—being suspicious of something doesn't equal having a logical foundation for a damning conclusion about it.

Incorrect. This is also too strong. We don't know that Grocerytown has higher prices overall. It's entirely possible that it has lower prices on average, but BigFoods charges less for the specific items in the survey.

Correct. Argument or Facts:
Facts

Question Type:
Must Be True

Stimulus Summary:
BigFoods, according to their own ad, surveyed customers to figure out what items they buy most, then compared prices on some of those items to the prices at Grocerytown. On average, BigFoods was charging 10% less (regular pricing, not on sale) for the items they compared.

Answer Anticipation:
The stimulus doesn't support any very strong conclusions. Look at this weak, limiting language: "a varied sample." Not only did they start with just their shoppers' favorite items—maybe those are specific items they buy at BigFoods because they know the chain charges less for them, even though it's pricier than Grocerytown overall—then then compared only "a varied sample," not, say, the 100 most popular items. Basically, they picked and chose, so we can't justify any conclusions like "BigFoods is a cheaper place to shop" or "BigFoods has better prices on popular items." Expect something very week that essentially rephrases the results here: when you are very selective in your sample, you can find some foods that are priced 10% lower on average at BigFoods than at Grocerytown.

Answer Explanation:
Nice and weak here, especially by starting with a "some," which is always attractive on a "most strongly supported" Must Be True. Remember, "some" means at least one, and the stimulus does give us grounds to believe there is at least one popular item that's less expensive at BigFoods. This works perfectly for our criteria here.

Key Takeaway:
Every most strongly supported question is basically a test of your understanding of logical force. Unless you're really quite sure that the stimulus supports a strong conclusion, avoid absolute statements, in other words those that could be prefaced with "all." As in, "(All) shoppers who usually patronize Grocerytown . . . " A prejudice towards weak answer choices with the word "some" in them will serve you well on most, though perhaps not all, most strongly supported Must Be True questions.

Incorrect. Again, this is unsupported by the stimulus. We know BigFoods wasn't having a sale on these items. We don't get any information about their sale status at Grocerytown.

Incorrect. This is unsupported as well. Nothing in the stimulus tells us that these aren't the most popular items at Grocerytown, too. Maybe BigFoods really does have lower prices on the most popular stuff in store!