standard deviation



hi there
I am new here and I want some assistance to solve my problem. I have 6 tables, each table has two column (time vs distance). it was set the final value for all the distance in each table to 23.5 but the time required to reach that value was different. for example table 1 needs 15 min to reach 23.5 while the second table shows 20 min to reach 23.5 and so on. the question is how can I calculate the standard deviation and error bar for these tables?


A. W.