A made-up primary school tests eight children: four aged 8 and four aged 11…

A made-up primary school tests eight children: four aged $8$ and four aged $11$. For the younger children, shoe sizes $30$, $31$, $32$ and $33$ go with reading scores $42$, $40$, $45$ and $41$. For the older children, sizes $35$, $36$, $37$ and $38$ go with scores $61$, $64$, $60$ and $63$. Find $r$ inside each age group and for all eight children, to three decimal places. What do you conclude?