A.偶然故障 B.必然故障 C.耗損故障 D.致命性故障 E.非致命性故障
A.1.0~100 B.0.01~10 C.0.01~100 D.0.1~1000
某種食物中鈣的含量服從正態(tài)分布,從中抽取容量n=11的樣本,
A.[2.109,121.05] B.[2.258,121.05] C.[2.258,142.28] D.[2.109,142.28]