How many significant figures does a standard deviation have? Is this based on the number of sig figs in the mean and or data set?

If I have data points of {50.1, 52.2, 51.9} I assume the mean would also have 3 sig figs = (51.4). The sample standard deviation is 1.135782. Do I round that to 3 sig figs or is there a special rule here? If you use sig figs through the standard deviation calculation you would get three sig figs, but sometime you lose sig figs because the variance is very small.

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