Answer
The internet shopping revenues is expected to be around $\$624.5$ billion in 2015.
Work Step by Step
2015 is 12 years after 2003 so $t=12$.
Substitute 12 to $t$ in the given equation to have:
$\\y=39(1.26)^t
\\y=39(1.26)^{12}
\\y=624.4693803
\\y\approx 624.5$
