Table 2 Within-family variance ( ${\mathbf{\sigma }}_{\mathit{w}}^{\mathbf{2}}$ ) and number of records per family ( m ) for three group compositions

$\frac{1}{\mathit{n}}\left({\mathrm{\sigma }}_{{\mathit{P}}_{\mathrm{D}}}^2+2\left(\mathit{n}-1\right){\mathrm{\sigma }}_{{\mathit{P}}_{\mathrm{DI}}}+{\left(\mathit{n}-1\right)}^2{\mathrm{\sigma }}_{{\mathit{P}}_{\mathrm{I}}}^2+\left(\mathit{n}-1\right)\mathit{r}{\mathrm{\sigma }}_{{\mathit{A}}_{\mathrm{T}}}^2\right)-\mathit{r}{\mathrm{\sigma }}_{{\mathit{A}}_{\mathrm{T}}}^2$

o/n

$\frac{4}{\mathit{n}}\left({\mathrm{\sigma }}_{{\mathit{P}}_{\mathrm{D}}}^2+2\left(\mathit{n}-1\right){\mathrm{\sigma }}_{{\mathit{P}}_{\mathrm{DI}}}+{\left(\mathit{n}-1\right)}^2{\mathrm{\sigma }}_{{\mathit{P}}_{\mathrm{I}}}^2+\left(\frac{\mathit{n}}{2}-1\right)\mathit{r}{\mathrm{\sigma }}_{{\mathit{A}}_{\mathrm{T}}}^2\right)-\mathit{r}{\mathrm{\sigma }}_{{\mathit{A}}_{\mathrm{T}}}^2$

2o/n

$\mathit{n}\left({\mathrm{\sigma }}_{{\mathit{P}}_{\mathrm{D}}}^2+2\left(\mathit{n}-1\right){\mathrm{\sigma }}_{{\mathit{P}}_{\mathrm{DI}}}+{\left(\mathit{n}-1\right)}^2{\mathrm{\sigma }}_{{\mathit{P}}_{\mathrm{I}}}^2\right)-\mathit{r}{\mathrm{\sigma }}_{{\mathit{A}}_{\mathrm{T}}}^2$

o