It is convenient to let a calculator or spreadsheet program compute the means and standard deviations for you. The (mean, standard deviation) for the two groups are about ...
... group 1: (320, 8.2)
... group 2: (325, 2.9)
The mean of the measurements of Group 1 was closer to the actual value, so we can say that group was more accurate.
The variation was smaller for Group 2, so we can say that group was more precise.
