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What is approximate standard deviation for the list of

numbers: 10.4, 9.8, 10.0, 9.2, 10.5, 9.8, 9.9, 10.1,

10.4, 10.2, 10.7, 9.6?

A. 2.1 B. 1.9 C. 1.75 D. 1.8

The question shows up on my kid's test recently.

The standard deviation is 0.42. Why can the answer be C.

1.75?

If 0.42 is the correct standard deviation, the answer

choice 1.75 is TOO LARGE to be called an "approximate",

so there is not a valid or or reasonable answer. So, the

question is not valid and should be excluded from the

test score.

Anyone agreee? Please correct me if my thoughts are

wrong.

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closed as unclear what you're asking by Namaste, Leucippus, kimchi lover, Xander Henderson, Lord Shark the Unknown Sep 16 '17 at 6:34

Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

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I think you're exactly right. None of those answers are really even close to the actual standard deviation.

Choice C is the closest of the four, but it's still way off.

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  • $\begingroup$ Truly weird. Answers (c) and (d) are only 0.05 apart yet (c) is 1.33 from the right answer - and the kid is supposed to be approximating !?! $\endgroup$ – MaxW Sep 9 '16 at 21:40

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