A:
B:
C:
D:x2-3y=0
已知某批零件的长度误差(单位:毫米)服从正态分布 ,从中随机取一件,其长度误差落在区间(3,6)内的概率为( )
(附:若随机变量ξ服从正态分布 ,则 , 。)
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Chen Jie and Chen Lin are sisters. Chen Jie is 14. She's 2 years younger than Chen Lin. But she's taller than Chen Lin. Chen Jie is 46 kilograms. She's l kilogram heavier than Chen Lin. Chen Jie likes sports. She plays sports every day. So she's stronger than Chen Lin. Chen Jie has short hair, but Chen Lin has long hair. They often wear the same size shoes. They wear size 36. They love each other.