• 2022-05-26
    总体X服从正态分布[img=71x27]1803a75189f584c.png[/img],总体Y服从正态分布[img=71x27]1803a7519321985.png[/img],[img=91x24]1803a7519bfa2d6.png[/img]和[img=82x24]1803a751a527f35.png[/img]分别是来自总体X和Y的简单随机样本,则[img=210x68]1803a751afe4c27.png[/img]=( )
    A: [img=18x22]1803a751b869607.png[/img]
    B: [img=103x27]1803a751c0aeac6.png[/img]
    C: [img=38x27]1803a751ca122bf.png[/img]
    D: [img=29x22]1803a751d3f7b4b.png[/img]
  • 举一反三