Answer
$$ A\approx 1,342,000 \ mi^2$$
Work Step by Step
We find the area of each area:
$$ A = \pi \times (15 \ mi)^2 \\ A = 707 \ mi^2 $$
Thus, for the 1900 areas, the total area covered is:
$$ A = (707\ mi^2 )(1900) \\ A\approx 1,342,000 \ mi^2$$
