Trick question with wording?

[Rastis]

If a group of numbers has an average of 1 and a standard deviation of 2, then how many integers are within one standard deviation of the average?

a) 2
b) 4
c) 5
d) 8
e) 9

I believe the answer is 3, which is not listed as an answer choice. The question asks "WITHIN" one standard deviation. To me, that does not mean inclusive of the standard deviation itself. Can someone help explain this? After doing countless problems where the questions include "inclusive", suddenly throwing a curveball like this isn't good.

[regor60]

If a group of numbers has an average of 1 and a standard deviation of 2, then how many integers are within one standard deviation of the average?

a) 2
b) 4
c) 5
d) 8
e) 9

I believe the answer is 3, which is not listed as an answer choice. The question asks "WITHIN" one standard deviation. To me, that does not mean inclusive of the standard deviation itself. Can someone help explain this? After doing countless problems where the questions include "inclusive", suddenly throwing a curveball like this isn't good.

Well, as long as questions like this that can be interpreted in different ways offer only one of those as an answer, it should be fine.

The concern would be if answer choices included both 3 and 5

[DavidG@VeritasPrep]

If a group of numbers has an average of 1 and a standard deviation of 2, then how many integers are within one standard deviation of the average?

a) 2
b) 4
c) 5
d) 8
e) 9

I believe the answer is 3, which is not listed as an answer choice. The question asks "WITHIN" one standard deviation. To me, that does not mean inclusive of the standard deviation itself. Can someone help explain this? After doing countless problems where the questions include "inclusive", suddenly throwing a curveball like this isn't good.

This appears to be a flawed question. See here for a discussion on an official question that tests the concept in a clear way: https://www.beatthegmat.com/gmat-prep-qu ... 77848.html

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Hi Rastis,

GMAT questions are always carefully worded so that 'bias' on the part of the reader can be eliminated. In the event that a question can be interpreted more than one way, the ANSWER choices tend to be written so that only one answer is correct (and not two different answers).

In regards to this specific prompt, it does NOT state "how many integers are LESS than one standard deviation away from the average?" The answer to THAT question would be 3: the numbers 0, 1 and 2.

The usage of the word "WITHIN", in this context, means 'inclusive." So the answer to this question is 5: the numbers -1, 0, 1, 2 and 3.

GMAT assassins aren't born, they're made,
Rich

[Matt@VeritasPrep]

Well, as long as questions like this that can be interpreted in different ways offer only one of those as an answer, it should be fine.

The concern would be if answer choices included both 3 and 5

This is how I'd handle it on the test; 3's not there, so it must be 5. It is an interesting question, though: I've personally never encountered a situation where I had to judge whether "within one SD" meant ≤ 1 or < 1.