Plot[PDF[ChiSquareDistribution[5],x],{x,0,20}]

Plot[{PDF[ChiSquareDistribution[10],x],PDF[ChiSquareDistribution[7],x],PDF[ChiSquareDistribution[5],x]},{x,0,25}]

ListPlot[Table[{k,PDF[BinomialDistribution[8,p],k]},{p,{0.3,0.5,0.8}},{k,0,8}],PlotMarkers->Automatic,Joined->True,PlotRange->All]

ListPlot[Table[{k,PDF[PoissonDistribution[10],k]},{k,0,30}],Filling->Axis]

ListPlot[Table[{k,PDF[PoissonDistribution[l],k]},{l,5, 13,2},{k,0,25}],PlotMarkers->Automatic,Joined->True,PlotRange->All]

ListPlot[Table[{k,PDF[PoissonDistribution[m],k]},{m,5, 13,3},{k,0,25}],PlotMarkers->Automatic,Joined->True,PlotRange->All]