Answer
$q(60)\approx 210$ million
Work Step by Step
Graphically:
Using the graphing device as in part (a), graph the line $x=60$ in the same window, and find the intersection point with the graph of the demand function.
Numerically:
$q(60)=0.0009\times 60\wedge 2-0.63\times 60+245\approx 210$ million