选项
A.
A.( S^2sim chi ^2(9) )
B.
B.(sumlimits_{i=1}^{10} {(X_i -bar {X})^2sim chi ^2(10)} )
C.
C.( sumlimits_{i=1}^5 {(X_{2i} -X_{2i-1} )^2} sim chi ^2(5) )
D.
D.(frac{1}{2}sumlimits_{i=1}^5 {(X_{2i} -X_{2i-1} )^2} sim chi ^2(5) )
正确答案：D
名词解析
由抽样分布定理可得。