magnitudes=Select[ExampleData[{"Statistics","USEarthquakes"}],#[[1]]≥1935&][[All,7]];

edist=EstimatedDistribution[magnitudes,MixtureDistribution[{p,1-p},{NormalDistribution[a,b],NormalDistribution[c,d]}]];

wts=Table[edist[[1,i]] PDF[edist[[2,i]],x],{i,2}];
h=Histogram[magnitudes,20,"ProbabilityDensity",ChartStyle->Directive[Opacity[.6],Hue[.242,.4,.8]]];
GraphicsRow[{Show[h,Plot[wts,{x,2,8},PlotStyle->{{Hue[.01,.6,.6],Thick},{Hue[.6,.7,.7],Thick}},PlotRange->All],PlotLabel->Style["PDF Components",FontFamily->"Verdana"]],Plot[Evaluate[Table[edist[[1,i]] PDF[edist[[2,i]],x]/Total[wts],{i,2}]],{x,3,7},PlotStyle->{{Hue[.01,.6,.6],Thick},{Hue[.6,.7,.7],Thick}},FillingStyle->{1->Directive[Opacity[.3],Hue[.01,.6,.6]],2->Directive[Opacity[.3],Hue[.6,.7,.7]]},PlotRange->All,Filling->Axis,PlotLabel->Style["Component Probabilities",FontFamily->"Verdana"]]}]