Answer
The model overestimates the percentage by $0.8$ percent.
Work Step by Step
Substituting a with 24 in the given formula, we find
$p=52-0,3\cdot a$
$p=52-0,3\cdot 24$
$=52-7.2$
$=52.0-7.2$
$=44.8 $ (percent)
The graph gives $44=44.0$,
so the model overestimates the value in the graph by $0.8 $ (percent).
$(44.8-44.0=0.8)$
The model overestimates the percentage by $0.8$ percent.