How do you explain the variability in the values?

a) Section Data for Water Weights Graduated Cylinder Pipetting Mean 7.85 Mean 7.77 Median 7.85 Median 7.77 Variance 0.008494896 Variance 0.005895652 S.D 0.09216776 S.D 0.07678315 01 7.77 Q1 7.745 03 7.925 03 7.82 IQR 0.155 IQR 0.075 b) Combined Data for Water Weights Graduated Cylinder Pipetting Mean 7.75 Mean 7.85 median 7.80 median 7.85 variance 0.0401 variance 0.0139 S.D 0.2003 S.D 0.1177 Q1 7.68 Q1 7.78 Q3 7.9 03 7.92 IQR 0.22 IOR 0.14