Is the standard deviation of a certain set greater than
15,000?
1). The range of the set is 25,000
2). The mean of the set is 150,000
OA : A
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STD Deviation
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adthedaddy
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Check Stuart's reply overhere: https://www.beatthegmat.com/standart-dev ... 30305.html
"Your time is limited, so don't waste it living someone else's life. Don't be trapped by dogma - which is living with the results of other people's thinking. Don't let the noise of others' opinions drown out your own inner voice. And most important, have the courage to follow your heart and intuition. They somehow already know what you truly want to become. Everything else is secondary" - Steve Jobs
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Ian Stewart
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You'd never need to know this on the GMAT, but the standard deviation won't ever be more than half the range. That's quite easy to prove if you have a symmetric set, and not at all easy to prove if you have an asymmetric set. It's also not a widely known or reported property of standard deviation, so there's no way any GMAT test taker could be expected to know it, nor could anyone reasonably be expected to prove it in anything close to 2 minutes.
So that's why the answer is A here, but you absolutely don't need to be even remotely concerned about this for the GMAT. Where is this question from?
So that's why the answer is A here, but you absolutely don't need to be even remotely concerned about this for the GMAT. Where is this question from?
For online GMAT math tutoring, or to buy my higher-level Quant books and problem sets, contact me at ianstewartgmat at gmail.com
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