The following density measurements were made on a bar of iron: 7.58 g/mL, 8.02 g/mL, 7.83 g/mL, 7.80 g/mL, and 7.66 g/mL. The accepted value for iron's density is 7.85 g/mL. Find:
1)The error of the average of this set of measurements?
2) The relative error of the average expressed as a percent?