Change of SD after data removal

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I was asked to analysis 3 data, and calculate their mean and standard deviation (SD) to report the data as mean +/- SD. However, since one of it lied out of +/- 1 SD, should it be rejected?

If yes, since SD cannot be calculated by 2 data, then how can I report the 2 data by mean +/- SD? Or I should take the original SD to report the data?

Much thanks in advance for answering.