How do I calculate errors in measurement?

Question

aaronq · Answer

it depends on what you measured, how you measured, and how many times you measured it

anonymous · Answer

I measured the diameter of 5 $1 coins by using the micrometer screw gauge. I got:
1) 16.76 mm
2) 17.3      "
3) 17.31    "
4) 17.3      "
5) 17.35    "

anonymous · Answer

Human error could possible be a factor with dimensions that small however its probably minor imperfections in each of the coins. Or depending on if they have ridges along the edges you could be measuring in a different part of the coin and get a different measurement.

anonymous · Answer

Thanks! I'll include that in my discussion.

aaronq · Answer

did the micrometer screw gauge have a manufacturer's error (or more accurately, uncertainty) listed on the instrument?

anonymous · Answer

I did not check but now it's too late anyways. I already handed in the lab. What I did was, I calculated the:
1) Mean
2) Deviation
3) Square of deviation
4)Variance
5) Standard deviation.

anonymous · Answer

But thanks anyways!