• 2022-05-31
    随机变量X只能取-1,0,1,2四个数值,其相应的概率依次为[img=17x43]18034eb50252207.png[/img],[img=17x43]18034eb50a7551a.png[/img],[img=17x43]18034eb512a3737.png[/img],[img=26x43]18034eb51bd2952.png[/img],则c=____.