2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/128361Here we develop a first order autoregressive model {Xn} that is marginally stationary where Xn is the sum/ extreme of k i.i.d observations. We prove that stationary solutions to these models are either semi-selfdecomposable/ extreme-semi-selfdecomposable or, sum/ extreme stable with respect to Harris distribution.13 pages, corrections made including typos, added journal reference, PDF formatProbabilityStatistics Theory60 E 07, 60 G 10, 62 E 10, 62 M 10text