Show, in the notation of Section 4.7.1, that if the scalar n22 = i,j,k,l i,j k,l is

Show, in the notation of Section 4.7.1, that if the scalar n22 =

ρi,j,k,lρ

i,jρ

k,l is non-zero, then n

−1 22 ρi,j,k,lρ

k,lRr;iRs;j is an invariant unbiased estimate of κ

r,s Under what circumstances is the above estimate the same as k r,s?