Oh wait, it may be that they want you to calculate the proper standard deviations of those measurements yourself.

Since they gave you a *mean *squared deviation, that would be the sum of the squared deviations, divided by the number of measurements.

However, the proper squared standard deviation, is the sum of the squared deviations, divided by the number of measurements* ***minus one**.

It would mean that you have to multiply the mean squared deviation by n/(n-1).

That is, in the case of the iron:$\displaystyle \text{squared standard deviation} = \text{mean squared deviation} \times {8 \over 8 - 1}$