• 2022-05-31
    随机变量[img=8x23]18033db036b4873.png[/img]只能取-1,0,1,2四个数值,其相应的概率依次为[img=17x43]18033db03e9ebb9.png[/img],[img=17x43]18033db04791229.png[/img],[img=17x43]18033db050bf799.png[/img],[img=26x43]18033db058763eb.png[/img],则c=____.