how do we get 1.1*10^-8

in details plz

Now assume a transmit power of 250 W at the earth station. What is the power received at the satellite antenna in dBW and in W? Convert to dB and plug into the path loss equation P+(dBW) = 10 log 10 (Pw/1W) = 23.9794 dBW Path Loss (dB) = 20 log(f) + 20 log(d) 147.56 Pr = Pt + Gains - Losses Pr = 23.9794 +44 + 48 - 195.57 Pr = -79.6 dBW Pr (dBW) = 10 log 10 (Pw/1W) Pr(W) = 1.1 * 10-8 W