• 2022-07-27
    设X~N(3,4),则下列式子一定成立的是_______.
    A: [img=171x25]1803da12a999070.png[/img]
    B: [img=171x25]1803da12b2b1355.png[/img]
    C: [img=203x29]1803da12c1f00ea.png[/img]
    D: [img=171x25]1803da12cafb6e1.png[/img]