2-1：（1）26.2025mm=26202.5um,26202.5-0.5=26202um
(2) 10次测量均值为 26.2025mm=26202.5um,26202.5-0.5=26202um
（3）26.2025mm,10次测量均值为 26.2025mm
2-2：测量结果的算术平均值为：28.504.观测值的残差为：0.026,0.016,0.006,0.016,0.026,0.026,-0.006,-0.016,-0.016,0.006,0.026,0.016,-0.016,-0.104,-0.004
实验标准偏差为：