An object is weighed four times, and the results, in milligrams, are 234, 236, 233, and 229. The object is then weighed four times on a different scale, and the results, in milligrams, are 236, 225, 245, and 240. The average of all eight measurements will be used to estimate the weight. Someone suggests estimating the uncertainty in this estimate as follows: Compute the standard deviation of all eight measurements. Call this quantity s. The uncertainty is then s/√8. Is this correct? Explain.