• 2022-06-07
    ​总体X服从正态分布[img=71x27]1802f2ca6c3f9ac.png[/img],总体Y服从正态分布[img=71x27]1802f2ca75a4933.png[/img],[img=91x24]1802f2ca7e3cec3.png[/img]和[img=82x24]1802f2ca86ec4d2.png[/img]分别是来自总体X和Y的简单随机样本,则[img=210x68]1802f2ca9144111.png[/img]=( )​
    A: [img=18x22]1802f2ca9a45713.png[/img]
    B: [img=103x27]1802f2caa3b1945.png[/img]
    C: [img=38x27]1802f2caac34ef2.png[/img]
    D: [img=29x22]1802f2cab46e2c5.png[/img]
  • 举一反三