(来学网)标准正态分布曲线下区间(-∞,+1)所对应的面积为()
  • A.
    (来学网)15.86%
  • B.
    (来学网)31.73%
  • C.
    (来学网)68.27%
  • D.
    (来学网)84.14%
  • E.
    (来学网)需查u界值表