• 2022-07-27
    设X~N(3,4),则下列式子一定成立的是_______.
    A: [img=171x25]18035734a47ac36.png[/img]
    B: [img=171x25]18035734ac45d48.png[/img]
    C: [img=203x29]18035734b877a06.png[/img]
    D: [img=171x25]18035734c092ec5.png[/img]