for my coursework I'm meant to do error calculations. say i measured a distance between two things five times and got these results: 0.104 0.104 0.104 0.108 0.108 now i've got to use this distance for my calculations. would you recommend i use an average (mean)? i suppose that's a stupid question. my teacher also says: "You would get an estimate of random error by repeating results enough times to get a standard deviation for the random error. " so does this mean, for my example listed above, that i would say the error is (+-) value of s.d?