A piece of metal was weighed on a laboratory balance five times and gave the following values: 15.75, 15.73, 15.77, 15.76 and 15.74 grams. Determine the average mass and standard deviation from the...

A piece of metal was weighed on a laboratory balance five times and gave the following values: 15.75, 15.73, 15.77, 15.76 and 15.74 grams. Determine the average mass and standard deviation from the mean mass. (b) An object weighs 0.0930 grams on an analytical balance. Indicate the accuracy of the balance and the number of significant figures in this weight.