<< Graphics`Graphics`
P[x_] := (1/(Sqrt[2  π σ])) (E^(((-(((x - μ))^2))/(2  σ))))
i := 100
ΔL := 1
p := (1/2)
μ := i (2  p - 1) ΔL
σ := 
      i (1 - (p - (((1 - p))^2))) Δ(L^2)
data1 := 
      Partition[
        ReadList["C:\PDEHW2.TXT", Number, 
          RecordSeparators ->  {","}], 
        3]
g1 := 
      GeneralizedBarChart[data1, 
        PlotRange -> {0, 0.08}]
g2 := 
      Plot[P[x], {x, -100, 100}, PlotRange  ->  {0, 0.05}, 
        PlotStyle -> {RGBColor[0.5, 0.5, 0.7], 
            Thickness[0.01]}]
Show[g1, g2, PlotRange -> {0, 0.09}]