Answer
$ a.\quad$ model 1
$ b.\quad$ underestimates by ${{\$}} 593$
Work Step by Step
$ a.\quad$
In 2001, x is 1 (1 year after 2000).
Model 1: $D=1188(1)+16,218=17,406$
Model 2: $D=46(1)+541(1)+17650={{\$}} 18,237$
The graph reads ${{\$}} 17,562$, so model 1 gives a closer (better) estimate for that year.
$ b.\quad$
In 2103, x is 3 (3 years after 2000).
Model 2 estimates:
$D= 46(13^{2})+541(13)+17,650={{\$}} 32,457,$
which is less than the figure given in the chart, ${{\$}} 33,050$.
Subtracting $33,050-32,457=593$
