E(X)=∫[c,+∞)x*β^α/Γ(α)*(x-c)^(α-1)*e^[-β(x-c)]*dx (α>0,β>0)=∫[0,+∞)(t/β+c)*β^α/Γ(α)*(t/β)^(α-1)*e^(-t)*1/β*dt=1/Γ(α)*∫[0,+∞){t^[(α+1)-1]/β+ct^(α-1)}e^(-t)dt=1/Γ(α)*[1/β*...