设随机变量X,Y,Z独立,并且都服从正态分布[img=54x25]1803209f68c69f6.png[/img],令W=[img=123x44]1803209f717a93f.png[/img],则( )
A: [img=138x43]1803209f791d1d7.png[/img]
B: [img=136x43]1803209f817f6e1.png[/img]
C: [img=138x43]1803209f89d2ae0.png[/img]
D: [img=100x43]1803209f92a5dc6.png[/img]
E: [img=100x43]1803209f9ba79d5.png[/img]
A: [img=138x43]1803209f791d1d7.png[/img]
B: [img=136x43]1803209f817f6e1.png[/img]
C: [img=138x43]1803209f89d2ae0.png[/img]
D: [img=100x43]1803209f92a5dc6.png[/img]
E: [img=100x43]1803209f9ba79d5.png[/img]
举一反三
- 设随机变量X,Y,Z独立,并且都服从正态分布[img=54x25]1803214e7f6b54c.png[/img],令W=[img=123x44]1803214e87aad4b.png[/img],则( ) A: [img=138x43]1803214e8fa583d.png[/img] B: [img=136x43]1803214e97a5117.png[/img] C: [img=138x43]1803214ea067135.png[/img] D: [img=100x43]1803214ea9d2e92.png[/img] E: [img=100x43]1803214eb2fbdfd.png[/img]
- 设随机变量X,Y,Z独立,并且都服从正态分布[img=54x25]180320918bcf9ce.png[/img],令W=[img=123x44]1803209193fd1a2.png[/img],则( ) A: [img=138x43]180320919cdb05e.png[/img] B: [img=136x43]18032091a5a423c.png[/img] C: [img=138x43]18032091ae9094e.png[/img] D: [img=100x43]18032091b757c4b.png[/img] E: [img=100x43]18032091bfc68e6.png[/img]
- 设随机变量X的概率密度为f(x),则f(x)一定满足( ). A: 0≤f(x)≤1 B: [img=183x53]1803b451bb3373a.png[/img] C: [img=133x51]1803b451c807078.png[/img] D: f(+∞)=1
- 可导函数f(x),对任意的x,y恒有f(x+y)=f(x)f(y),且f'(0)=1,则f(x)等于 A: [img=60x19]1802fb229b3bc18.png[/img] B: [img=55x46]1802fb22a3b7107.png[/img] C: [img=17x19]1802fb22abf3c5e.png[/img] D: [img=49x23]1802fb22b545827.png[/img]
- 设X的密度函数为f(x),分布函数为F(x),并且f(x)=f(-x)。那么对任意给定的a>0都有 A: [img=170x49]18038fe676863cb.png[/img] B: [img=176x49]18038fe680a68a4.png[/img] C: F(a)=F(-a) D: F(-a)=2F(a)-1