A laboratory instructure gives a sample of Amino-powder to each if four students,1,2,3 and 4,and they weigh the samples.The true value is 8.72g.Their results for three trails are (1),8.72g,8.74g,8.70g (2),8.56g,8.77g,8.83g (3),8.50g,8.48g,8.51g (4),8.41g,8.72g,8.55g
(A)calculate the average mass from each set of data,and tell which set is the most accurate.