Is my Chemistry book wrong on the significant figures in this exercise? Why did they round to 0.16 instead of 0.1580 ?

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Also why did they round down the means?

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  • $\begingroup$ why the thumbs down? $\endgroup$
    – eromod
    Sep 12, 2016 at 4:51
  • $\begingroup$ Your question has little to nothing to do with significant figures, you are calculating the standard deviation, ordinary rounding rules apply. As for the down-vote I can only speculate: You used excessive markup, some people really dislike that. It also would have been better to explain, why you think it should have been one value instead of another. Give more context to your thoughts to avoid down-votes. $\endgroup$ Jan 16, 2017 at 7:42

1 Answer 1


I figured it out.

The means are rounded to only two sig figs because its subtraction. And significant figures follow different rules under subtraction/addition vs multiplication/division.

And its 0.16 for the same reason that the means are only two sig figs. Because its addition, not multiplication/division.

derp, two hours down the drain


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