• 2022-07-27
    设X~N(3,4),则下列式子一定成立的是
    A: [img=171x25]1803da10c8790f7.png[/img]
    B: [img=171x25]1803da10d0c82ce.png[/img]
    C: [img=203x29]1803da10ddc0186.png[/img]
    D: [img=171x25]1803da10e6959d9.png[/img]