data={{Log[1],Log[13]},{Log[1/2],Log[49]},{Log[1/4],Log[186]},{Log[1/8],Log[653]}}

data1=N[{{Log[1],Log[13]},{Log[1/2],Log[49]},{Log[1/4],Log[186]},{Log[1/8],Log[653]}}]

line = Fit[data,{1,x},x]

Show[ListPlot[data, PlotStyle->Red,AspectRatio->Automatic], Plot[{line}, {x, -3,1}]]