Answer
a) Model 2
b) overestimate; \$5
Work Step by Step
a) In order to determine which model best represents the data provided in the chart, start by plugging in 0 for $x$, as it represents 2007 (the chart portrays years after 2007). When 0 is plugged into model 1, the average price of a TV is \$890, while in model 2, it is \$950. The average price shown by the graph is \$935, making model 2 closer to the graph value of \$935.
b)To find the average price of a TV in 2012 (5 years after 2007), plug 5 into $x$ for the model 2 equation (polynomial model of degree 2): $18(5)^{2}-175(5)+950=525$. This overestimates the graph value of \$520 by \$5.