Answer
For 66-year-olds, the model overestimates the percentage by $0.2$ percent.
Work Step by Step
Substituting a with $66$ in the given formula, we find
$p=52-0.3\cdot a$
$p=52-0.3\cdot 66$
$=52-19.8$
$=52.0-19.8$
$=32.2 $ (percent)
The graph gives $32=32.0$,
so the model overestimates the value in the graph by $0.2 $ (percent).
$(32.2-32.0=0.2)$
