Answer
$ a.\quad $
$69$
In 1990 (10 years after 1980), the wage gap was $69\%.$
The point $(10,69) $lies on the graph.
$ b.\quad $
$G(10)$ underestimates the actual data by $ 2\%$
Work Step by Step
$ a.\quad$
$G(10)=-0.01(10^{2})+10+60=69$
In 1990 (10 years after 1980), the wage gap was $69\%.$
The point $(10,69) $lies on the graph.
$ b.\quad $
The bar graph gives the value to be $ 71\%$, when x=10 (in the year 1990).
So, with $ 69\%$, the model $G(x)$
underestimates the actual data by $ 2\%$
