下列哪种情况说明存在异方差( )
A: [img=87x25]18031b6466423c6.png[/img]
B: [img=87x26]18031b646eb55df.png[/img], i≠j
C: [img=102x27]18031b64772838c.png[/img] (常数)
D: [img=106x27]18031b647fbdd23.png[/img]
A: [img=87x25]18031b6466423c6.png[/img]
B: [img=87x26]18031b646eb55df.png[/img], i≠j
C: [img=102x27]18031b64772838c.png[/img] (常数)
D: [img=106x27]18031b647fbdd23.png[/img]
举一反三
- 下列哪种情况说明存在异方差( ) A: [img=87x25]18033b70bafaf0c.png[/img] B: [img=87x26]18033b70c46385a.png[/img], i≠j C: [img=102x27]18033b70cd4984d.png[/img] (常数) D: [img=106x27]18033b70d50f9bc.png[/img]
- 若随机变量X的方差D(X)存在,a为常数,则[img=249x67]1802f2c16f96412.png[/img] A: D(X) B: 1 C: [img=58x66]1802f2c17877038.png[/img] D: a 2D(X)
- 若随机变量X的方差D(X)存在,a为常数,则[img=249x67]1802f2c2b6e46d0.png[/img] A: D(X) B: 1 C: [img=58x66]1802f2c2bf3c80f.png[/img] D: a 2D(X)
- 若随机变量X的方差D(X)存在,a为常数,则[img=249x67]18031e9705442a0.png[/img] A: D(X) B: 1 C: [img=58x66]18031e970dc4937.png[/img] D: a 2D(X)
- 若随机变量X的方差D(X)存在,a为常数,则[img=249x67]1803c07cf914aaa.png[/img] A: D(X) B: 1 C: [img=58x66]1803c07d00c9eff.png[/img] D: a 2D(X)