Let X1, ..., Xn be i.i.d. random variables having the Lebesgue p.d.f. θ-1e-(x-θ)/θI(θ,∞)(x), where θ > 0 is an unknown parameter.
(a) Find a statistic that is minimal sufficient for θ.
(b) Show whether the minimal sufficient statistic in (a) is complete.