To solve the problem it is necessary to address the concepts of power and intensity of a wave. The intensity of one is uniformly distributed over a distance, is proportional to power and inversely proportional to the square of the distance from the source.
Theoretically it is expressed as
[tex]I = \frac{P}{4\pi r^2}[/tex]
Re-arrange for P,
[tex]P = I(4\pi r^4)[/tex]
Replacing with our values we have
[tex]P=4\pi(1350)(1.5*10^{11})[/tex]
[tex]P= 3.815*10^{26}W[/tex]
Therefore the average power output of the sun is [tex]3.815*10^{26}W[/tex]
